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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 4f69f46d3dd2b0907126fd8d2567b727086c4aa7 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]25 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]26 <li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikovc6c98af2007-04-29 18:02:48 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]29 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]30 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]31 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]32 </ol>
33 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]34 <li><a href="#typesystem">Type System</a>
35 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]36 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]37 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]38 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]39 <li><a href="#t_floating">Floating Point Types</a></li>
40 <li><a href="#t_void">Void Type</a></li>
41 <li><a href="#t_label">Label Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]42 </ol>
43 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]44 <li><a href="#t_derived">Derived Types</a>
45 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]46 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]47 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]48 <li><a href="#t_function">Function Type</a></li>
49 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]50 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]51 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]52 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]53 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]54 </ol>
55 </li>
56 </ol>
57 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]58 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]59 <ol>
60 <li><a href="#simpleconstants">Simple Constants</a>
61 <li><a href="#aggregateconstants">Aggregate Constants</a>
62 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
63 <li><a href="#undefvalues">Undefined Values</a>
64 <li><a href="#constantexprs">Constant Expressions</a>
65 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]66 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]67 <li><a href="#othervalues">Other Values</a>
68 <ol>
69 <li><a href="#inlineasm">Inline Assembler Expressions</a>
70 </ol>
71 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]72 <li><a href="#instref">Instruction Reference</a>
73 <ol>
74 <li><a href="#terminators">Terminator Instructions</a>
75 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]76 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
77 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]78 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
79 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]80 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]81 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]82 </ol>
83 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]84 <li><a href="#binaryops">Binary Operations</a>
85 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]86 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
87 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
88 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]89 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
90 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
91 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]92 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
93 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
94 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]95 </ol>
96 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]97 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
98 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]99 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
100 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
101 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]102 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]103 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]104 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]105 </ol>
106 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]107 <li><a href="#vectorops">Vector Operations</a>
108 <ol>
109 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
110 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
111 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]112 </ol>
113 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]114 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]115 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]116 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
117 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
118 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]119 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
120 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
121 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]122 </ol>
123 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]124 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]125 <ol>
126 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
127 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
128 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
129 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
130 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]131 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
132 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
133 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
134 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]135 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
136 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]137 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]138 </ol>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]139 <li><a href="#otherops">Other Operations</a>
140 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]141 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
142 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]143 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]144 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]145 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]146 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]147 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]148 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]149 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]150 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]151 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]152 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
154 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]155 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
156 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
157 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]158 </ol>
159 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]160 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
161 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]162 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
163 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
164 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]165 </ol>
166 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]167 <li><a href="#int_codegen">Code Generator Intrinsics</a>
168 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]169 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
170 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
171 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
172 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
173 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
174 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
175 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]176 </ol>
177 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]178 <li><a href="#int_libc">Standard C Library Intrinsics</a>
179 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]180 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
181 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
182 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
183 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
184 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]185 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
186 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
187 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]188 </ol>
189 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]190 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]191 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]192 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]193 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
194 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
195 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]196 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
197 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]198 </ol>
199 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]200 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]201 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]202 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]203 <ol>
204 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]205 </ol>
206 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]207 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]208 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]209 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]210 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]211 </ol>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]212 <ol>
213 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]214 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]215 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]216 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]217 </ol>
218 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]219</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]220
221<div class="doc_author">
222 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
223 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]224</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]225
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]226<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]227<div class="doc_section"> <a name="abstract">Abstract </a></div>
228<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]229
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]230<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]231<p>This document is a reference manual for the LLVM assembly language.
232LLVM is an SSA based representation that provides type safety,
233low-level operations, flexibility, and the capability of representing
234'all' high-level languages cleanly. It is the common code
235representation used throughout all phases of the LLVM compilation
236strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]237</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]238
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]239<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]240<div class="doc_section"> <a name="introduction">Introduction</a> </div>
241<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]242
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]243<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]244
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]245<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]246different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]247representation (suitable for fast loading by a Just-In-Time compiler),
248and as a human readable assembly language representation. This allows
249LLVM to provide a powerful intermediate representation for efficient
250compiler transformations and analysis, while providing a natural means
251to debug and visualize the transformations. The three different forms
252of LLVM are all equivalent. This document describes the human readable
253representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]254
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]255<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]256while being expressive, typed, and extensible at the same time. It
257aims to be a "universal IR" of sorts, by being at a low enough level
258that high-level ideas may be cleanly mapped to it (similar to how
259microprocessors are "universal IR's", allowing many source languages to
260be mapped to them). By providing type information, LLVM can be used as
261the target of optimizations: for example, through pointer analysis, it
262can be proven that a C automatic variable is never accessed outside of
263the current function... allowing it to be promoted to a simple SSA
264value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]266</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]267
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]268<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]269<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]270
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]271<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]272
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]273<p>It is important to note that this document describes 'well formed'
274LLVM assembly language. There is a difference between what the parser
275accepts and what is considered 'well formed'. For example, the
276following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]277
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]278<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]279<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]280%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]281</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]282</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]283
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]284<p>...because the definition of <tt>%x</tt> does not dominate all of
285its uses. The LLVM infrastructure provides a verification pass that may
286be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]287automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]288the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]289by the verifier pass indicate bugs in transformation passes or input to
290the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]291</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]292
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]293<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]294
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]295<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]296<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]297<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]298
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]299<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]300
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]301 <p>LLVM identifiers come in two basic types: global and local. Global
302 identifiers (functions, global variables) begin with the @ character. Local
303 identifiers (register names, types) begin with the % character. Additionally,
304 there are three different formats for identifiers, for different purposes:
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]305
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]306<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]307 <li>Named values are represented as a string of characters with their prefix.
308 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
309 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]310 Identifiers which require other characters in their names can be surrounded
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]311 with quotes. In this way, anything except a <tt>&quot;</tt> character can
312 be used in a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]313
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]314 <li>Unnamed values are represented as an unsigned numeric value with their
315 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]316
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]317 <li>Constants, which are described in a <a href="#constants">section about
318 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]319</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]320
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]321<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]322don't need to worry about name clashes with reserved words, and the set of
323reserved words may be expanded in the future without penalty. Additionally,
324unnamed identifiers allow a compiler to quickly come up with a temporary
325variable without having to avoid symbol table conflicts.</p>
326
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]327<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]328languages. There are keywords for different opcodes
329('<tt><a href="#i_add">add</a></tt>',
330 '<tt><a href="#i_bitcast">bitcast</a></tt>',
331 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]332href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]333and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]334none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]335
336<p>Here is an example of LLVM code to multiply the integer variable
337'<tt>%X</tt>' by 8:</p>
338
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]339<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]340
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]341<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]342<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]343%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]344</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]345</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]346
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]347<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]348
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]349<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]350<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]351%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]352</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]353</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]354
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]355<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]356
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]357<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]358<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]359<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
360<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
361%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]362</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]363</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]364
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]365<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
366important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]367
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]368<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]369
370 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
371 line.</li>
372
373 <li>Unnamed temporaries are created when the result of a computation is not
374 assigned to a named value.</li>
375
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]376 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]377
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]378</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]379
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]380<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]381demonstrating instructions, we will follow an instruction with a comment that
382defines the type and name of value produced. Comments are shown in italic
383text.</p>
384
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]385</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]386
387<!-- *********************************************************************** -->
388<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
389<!-- *********************************************************************** -->
390
391<!-- ======================================================================= -->
392<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
393</div>
394
395<div class="doc_text">
396
397<p>LLVM programs are composed of "Module"s, each of which is a
398translation unit of the input programs. Each module consists of
399functions, global variables, and symbol table entries. Modules may be
400combined together with the LLVM linker, which merges function (and
401global variable) definitions, resolves forward declarations, and merges
402symbol table entries. Here is an example of the "hello world" module:</p>
403
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]404<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]405<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]406<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
407 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]408
409<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]410<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]411
412<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]413define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]414 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]415 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]416 href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]417
418 <i>; Call puts function to write out the string to stdout...</i>
419 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]420 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]421 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]422 href="#i_ret">ret</a> i32 0<br>}<br>
423</pre>
424</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]425
426<p>This example is made up of a <a href="#globalvars">global variable</a>
427named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
428function, and a <a href="#functionstructure">function definition</a>
429for "<tt>main</tt>".</p>
430
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]431<p>In general, a module is made up of a list of global values,
432where both functions and global variables are global values. Global values are
433represented by a pointer to a memory location (in this case, a pointer to an
434array of char, and a pointer to a function), and have one of the following <a
435href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]436
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]437</div>
438
439<!-- ======================================================================= -->
440<div class="doc_subsection">
441 <a name="linkage">Linkage Types</a>
442</div>
443
444<div class="doc_text">
445
446<p>
447All Global Variables and Functions have one of the following types of linkage:
448</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]449
450<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]451
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]452 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]453
454 <dd>Global values with internal linkage are only directly accessible by
455 objects in the current module. In particular, linking code into a module with
456 an internal global value may cause the internal to be renamed as necessary to
457 avoid collisions. Because the symbol is internal to the module, all
458 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]459 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]460 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]461
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]462 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]464 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
465 the same name when linkage occurs. This is typically used to implement
466 inline functions, templates, or other code which must be generated in each
467 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
468 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]469 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]470
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]471 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]472
473 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
474 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]475 used for globals that may be emitted in multiple translation units, but that
476 are not guaranteed to be emitted into every translation unit that uses them.
477 One example of this are common globals in C, such as "<tt>int X;</tt>" at
478 global scope.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]479 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]480
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]481 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]482
483 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
484 pointer to array type. When two global variables with appending linkage are
485 linked together, the two global arrays are appended together. This is the
486 LLVM, typesafe, equivalent of having the system linker append together
487 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]488 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]489
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]490 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
491 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
492 until linked, if not linked, the symbol becomes null instead of being an
493 undefined reference.
494 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]495
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]496 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]497
498 <dd>If none of the above identifiers are used, the global is externally
499 visible, meaning that it participates in linkage and can be used to resolve
500 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]501 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]502</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]503
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]504 <p>
505 The next two types of linkage are targeted for Microsoft Windows platform
506 only. They are designed to support importing (exporting) symbols from (to)
507 DLLs.
508 </p>
509
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]510 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]511 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
512
513 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
514 or variable via a global pointer to a pointer that is set up by the DLL
515 exporting the symbol. On Microsoft Windows targets, the pointer name is
516 formed by combining <code>_imp__</code> and the function or variable name.
517 </dd>
518
519 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
520
521 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
522 pointer to a pointer in a DLL, so that it can be referenced with the
523 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
524 name is formed by combining <code>_imp__</code> and the function or variable
525 name.
526 </dd>
527
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]528</dl>
529
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]530<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]531variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
532variable and was linked with this one, one of the two would be renamed,
533preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
534external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]535outside of the current module.</p>
536<p>It is illegal for a function <i>declaration</i>
537to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]538or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]539<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
540linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]541</div>
542
543<!-- ======================================================================= -->
544<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]545 <a name="callingconv">Calling Conventions</a>
546</div>
547
548<div class="doc_text">
549
550<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
551and <a href="#i_invoke">invokes</a> can all have an optional calling convention
552specified for the call. The calling convention of any pair of dynamic
553caller/callee must match, or the behavior of the program is undefined. The
554following calling conventions are supported by LLVM, and more may be added in
555the future:</p>
556
557<dl>
558 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
559
560 <dd>This calling convention (the default if no other calling convention is
561 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]562 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]563 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]564 </dd>
565
566 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
567
568 <dd>This calling convention attempts to make calls as fast as possible
569 (e.g. by passing things in registers). This calling convention allows the
570 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner8cdc5bc2005-05-06 23:08:23 +0000[diff] [blame]571 without having to conform to an externally specified ABI. Implementations of
572 this convention should allow arbitrary tail call optimization to be supported.
573 This calling convention does not support varargs and requires the prototype of
574 all callees to exactly match the prototype of the function definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]575 </dd>
576
577 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
578
579 <dd>This calling convention attempts to make code in the caller as efficient
580 as possible under the assumption that the call is not commonly executed. As
581 such, these calls often preserve all registers so that the call does not break
582 any live ranges in the caller side. This calling convention does not support
583 varargs and requires the prototype of all callees to exactly match the
584 prototype of the function definition.
585 </dd>
586
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]587 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]588
589 <dd>Any calling convention may be specified by number, allowing
590 target-specific calling conventions to be used. Target specific calling
591 conventions start at 64.
592 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]593</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]594
595<p>More calling conventions can be added/defined on an as-needed basis, to
596support pascal conventions or any other well-known target-independent
597convention.</p>
598
599</div>
600
601<!-- ======================================================================= -->
602<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]603 <a name="visibility">Visibility Styles</a>
604</div>
605
606<div class="doc_text">
607
608<p>
609All Global Variables and Functions have one of the following visibility styles:
610</p>
611
612<dl>
613 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
614
615 <dd>On ELF, default visibility means that the declaration is visible to other
616 modules and, in shared libraries, means that the declared entity may be
617 overridden. On Darwin, default visibility means that the declaration is
618 visible to other modules. Default visibility corresponds to "external
619 linkage" in the language.
620 </dd>
621
622 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
623
624 <dd>Two declarations of an object with hidden visibility refer to the same
625 object if they are in the same shared object. Usually, hidden visibility
626 indicates that the symbol will not be placed into the dynamic symbol table,
627 so no other module (executable or shared library) can reference it
628 directly.
629 </dd>
630
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]631 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
632
633 <dd>On ELF, protected visibility indicates that the symbol will be placed in
634 the dynamic symbol table, but that references within the defining module will
635 bind to the local symbol. That is, the symbol cannot be overridden by another
636 module.
637 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]638</dl>
639
640</div>
641
642<!-- ======================================================================= -->
643<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]644 <a name="globalvars">Global Variables</a>
645</div>
646
647<div class="doc_text">
648
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]649<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]650instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]651an explicit section to be placed in, and may have an optional explicit alignment
652specified. A variable may be defined as "thread_local", which means that it
653will not be shared by threads (each thread will have a separated copy of the
654variable). A variable may be defined as a global "constant," which indicates
655that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]656optimization, allowing the global data to be placed in the read-only section of
657an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]658cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]659
660<p>
661LLVM explicitly allows <em>declarations</em> of global variables to be marked
662constant, even if the final definition of the global is not. This capability
663can be used to enable slightly better optimization of the program, but requires
664the language definition to guarantee that optimizations based on the
665'constantness' are valid for the translation units that do not include the
666definition.
667</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]668
669<p>As SSA values, global variables define pointer values that are in
670scope (i.e. they dominate) all basic blocks in the program. Global
671variables always define a pointer to their "content" type because they
672describe a region of memory, and all memory objects in LLVM are
673accessed through pointers.</p>
674
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]675<p>A global variable may be declared to reside in a target-specifc numbered
676address space. For targets that support them, address spaces may affect how
677optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]678the variable. The default address space is zero. The address space qualifier
679must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]680
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]681<p>LLVM allows an explicit section to be specified for globals. If the target
682supports it, it will emit globals to the section specified.</p>
683
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]684<p>An explicit alignment may be specified for a global. If not present, or if
685the alignment is set to zero, the alignment of the global is set by the target
686to whatever it feels convenient. If an explicit alignment is specified, the
687global is forced to have at least that much alignment. All alignments must be
688a power of 2.</p>
689
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]690<p>For example, the following defines a global in a numbered address space with
691an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]692
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]693<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]694<pre>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]695@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]696</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]697</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]698
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]699</div>
700
701
702<!-- ======================================================================= -->
703<div class="doc_subsection">
704 <a name="functionstructure">Functions</a>
705</div>
706
707<div class="doc_text">
708
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]709<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
710an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]711<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]712<a href="#callingconv">calling convention</a>, a return type, an optional
713<a href="#paramattrs">parameter attribute</a> for the return type, a function
714name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]715<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]716optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]717opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]718
719LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
720optional <a href="#linkage">linkage type</a>, an optional
721<a href="#visibility">visibility style</a>, an optional
722<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]723<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]724name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]725<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]726
727<p>A function definition contains a list of basic blocks, forming the CFG for
728the function. Each basic block may optionally start with a label (giving the
729basic block a symbol table entry), contains a list of instructions, and ends
730with a <a href="#terminators">terminator</a> instruction (such as a branch or
731function return).</p>
732
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]733<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]734executed on entrance to the function, and it is not allowed to have predecessor
735basic blocks (i.e. there can not be any branches to the entry block of a
736function). Because the block can have no predecessors, it also cannot have any
737<a href="#i_phi">PHI nodes</a>.</p>
738
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]739<p>LLVM allows an explicit section to be specified for functions. If the target
740supports it, it will emit functions to the section specified.</p>
741
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]742<p>An explicit alignment may be specified for a function. If not present, or if
743the alignment is set to zero, the alignment of the function is set by the target
744to whatever it feels convenient. If an explicit alignment is specified, the
745function is forced to have at least that much alignment. All alignments must be
746a power of 2.</p>
747
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]748</div>
749
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]750
751<!-- ======================================================================= -->
752<div class="doc_subsection">
753 <a name="aliasstructure">Aliases</a>
754</div>
755<div class="doc_text">
756 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikova80e1182007-04-28 13:45:00 +0000[diff] [blame]757 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]758 optional <a href="#linkage">linkage type</a>, and an
759 optional <a href="#visibility">visibility style</a>.</p>
760
761 <h5>Syntax:</h5>
762
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]763<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]764<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]765@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]766</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]767</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]768
769</div>
770
771
772
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]773<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]774<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
775<div class="doc_text">
776 <p>The return type and each parameter of a function type may have a set of
777 <i>parameter attributes</i> associated with them. Parameter attributes are
778 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]779 a function. Parameter attributes are considered to be part of the function,
780 not of the function type, so functions with different parameter attributes
781 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]782
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]783 <p>Parameter attributes are simple keywords that follow the type specified. If
784 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]785 example:</p>
786
787<div class="doc_code">
788<pre>
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]789declare i32 @printf(i8* noalias , ...) nounwind
790declare i32 @atoi(i8*) nounwind readonly
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]791</pre>
792</div>
793
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]794 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
795 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]796
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]797 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]798 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]799 <dt><tt>zeroext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]800 <dd>This indicates that the parameter should be zero extended just before
801 a call to this function.</dd>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]802 <dt><tt>signext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]803 <dd>This indicates that the parameter should be sign extended just before
804 a call to this function.</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]805 <dt><tt>inreg</tt></dt>
806 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]807 possible) during assembling function call. Support for this attribute is
808 target-specific</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]809 <dt><tt>sret</tt></dt>
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]810 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]811 that is the return value of the function in the source program.</dd>
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]812 <dt><tt>noalias</tt></dt>
813 <dd>This indicates that the parameter not alias any other object or any
814 other "noalias" objects during the function call.
Reid Spencer2dc52012007-03-22 02:18:56 +0000[diff] [blame]815 <dt><tt>noreturn</tt></dt>
816 <dd>This function attribute indicates that the function never returns. This
817 indicates to LLVM that every call to this function should be treated as if
818 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]819 <dt><tt>nounwind</tt></dt>
820 <dd>This function attribute indicates that the function type does not use
821 the unwind instruction and does not allow stack unwinding to propagate
822 through it.</dd>
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]823 <dt><tt>nest</tt></dt>
824 <dd>This indicates that the parameter can be excised using the
825 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]826 <dt><tt>readonly</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]827 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]828 except for producing a return value or throwing an exception. The value
829 returned must only depend on the function arguments and/or global variables.
830 It may use values obtained by dereferencing pointers.</dd>
831 <dt><tt>readnone</tt></dt>
832 <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]833 function, but in addition it is not allowed to dereference any pointer arguments
834 or global variables.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]835 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]836
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]837</div>
838
839<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]840<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]841 <a name="gc">Garbage Collector Names</a>
842</div>
843
844<div class="doc_text">
845<p>Each function may specify a garbage collector name, which is simply a
846string.</p>
847
848<div class="doc_code"><pre
849>define void @f() gc "name" { ...</pre></div>
850
851<p>The compiler declares the supported values of <i>name</i>. Specifying a
852collector which will cause the compiler to alter its output in order to support
853the named garbage collection algorithm.</p>
854</div>
855
856<!-- ======================================================================= -->
857<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]858 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]859</div>
860
861<div class="doc_text">
862<p>
863Modules may contain "module-level inline asm" blocks, which corresponds to the
864GCC "file scope inline asm" blocks. These blocks are internally concatenated by
865LLVM and treated as a single unit, but may be separated in the .ll file if
866desired. The syntax is very simple:
867</p>
868
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]869<div class="doc_code">
870<pre>
871module asm "inline asm code goes here"
872module asm "more can go here"
873</pre>
874</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]875
876<p>The strings can contain any character by escaping non-printable characters.
877 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
878 for the number.
879</p>
880
881<p>
882 The inline asm code is simply printed to the machine code .s file when
883 assembly code is generated.
884</p>
885</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]886
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]887<!-- ======================================================================= -->
888<div class="doc_subsection">
889 <a name="datalayout">Data Layout</a>
890</div>
891
892<div class="doc_text">
893<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]894data is to be laid out in memory. The syntax for the data layout is simply:</p>
895<pre> target datalayout = "<i>layout specification</i>"</pre>
896<p>The <i>layout specification</i> consists of a list of specifications
897separated by the minus sign character ('-'). Each specification starts with a
898letter and may include other information after the letter to define some
899aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]900<dl>
901 <dt><tt>E</tt></dt>
902 <dd>Specifies that the target lays out data in big-endian form. That is, the
903 bits with the most significance have the lowest address location.</dd>
904 <dt><tt>e</tt></dt>
905 <dd>Specifies that hte target lays out data in little-endian form. That is,
906 the bits with the least significance have the lowest address location.</dd>
907 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
908 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
909 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
910 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
911 too.</dd>
912 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
913 <dd>This specifies the alignment for an integer type of a given bit
914 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
915 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
916 <dd>This specifies the alignment for a vector type of a given bit
917 <i>size</i>.</dd>
918 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
919 <dd>This specifies the alignment for a floating point type of a given bit
920 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
921 (double).</dd>
922 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
923 <dd>This specifies the alignment for an aggregate type of a given bit
924 <i>size</i>.</dd>
925</dl>
926<p>When constructing the data layout for a given target, LLVM starts with a
927default set of specifications which are then (possibly) overriden by the
928specifications in the <tt>datalayout</tt> keyword. The default specifications
929are given in this list:</p>
930<ul>
931 <li><tt>E</tt> - big endian</li>
932 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
933 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
934 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
935 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
936 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
937 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
938 alignment of 64-bits</li>
939 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
940 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
941 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
942 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
943 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
944</ul>
945<p>When llvm is determining the alignment for a given type, it uses the
946following rules:
947<ol>
948 <li>If the type sought is an exact match for one of the specifications, that
949 specification is used.</li>
950 <li>If no match is found, and the type sought is an integer type, then the
951 smallest integer type that is larger than the bitwidth of the sought type is
952 used. If none of the specifications are larger than the bitwidth then the the
953 largest integer type is used. For example, given the default specifications
954 above, the i7 type will use the alignment of i8 (next largest) while both
955 i65 and i256 will use the alignment of i64 (largest specified).</li>
956 <li>If no match is found, and the type sought is a vector type, then the
957 largest vector type that is smaller than the sought vector type will be used
958 as a fall back. This happens because <128 x double> can be implemented in
959 terms of 64 <2 x double>, for example.</li>
960</ol>
961</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]962
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]963<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]964<div class="doc_section"> <a name="typesystem">Type System</a> </div>
965<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]966
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]967<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]968
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]969<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]970intermediate representation. Being typed enables a number of
971optimizations to be performed on the IR directly, without having to do
972extra analyses on the side before the transformation. A strong type
973system makes it easier to read the generated code and enables novel
974analyses and transformations that are not feasible to perform on normal
975three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]976
977</div>
978
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]979<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]980<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]981Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]982<div class="doc_text">
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]983<p>The types fall into a few useful
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]984classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]985
986<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]987 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]988 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]989 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]990 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]991 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]992 </tr>
993 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]994 <td><a href="#t_floating">floating point</a></td>
995 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]996 </tr>
997 <tr>
998 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]999 <td><a href="#t_integer">integer</a>,
1000 <a href="#t_floating">floating point</a>,
1001 <a href="#t_pointer">pointer</a>,
1002 <a href="#t_vector">vector</a>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1003 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1004 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]1005 <tr>
1006 <td><a href="#t_primitive">primitive</a></td>
1007 <td><a href="#t_label">label</a>,
1008 <a href="#t_void">void</a>,
1009 <a href="#t_integer">integer</a>,
1010 <a href="#t_floating">floating point</a>.</td>
1011 </tr>
1012 <tr>
1013 <td><a href="#t_derived">derived</a></td>
1014 <td><a href="#t_integer">integer</a>,
1015 <a href="#t_array">array</a>,
1016 <a href="#t_function">function</a>,
1017 <a href="#t_pointer">pointer</a>,
1018 <a href="#t_struct">structure</a>,
1019 <a href="#t_pstruct">packed structure</a>,
1020 <a href="#t_vector">vector</a>,
1021 <a href="#t_opaque">opaque</a>.
1022 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1023 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1024</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1025
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1026<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1027most important. Values of these types are the only ones which can be
1028produced by instructions, passed as arguments, or used as operands to
1029instructions. This means that all structures and arrays must be
1030manipulated either by pointer or by component.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1031</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1032
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1033<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame^]1034<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
1035<div class="doc_text">
1036<p>The primitive types are the fundamental building blocks of the LLVM
1037system.</p>
1038
1039<!-- _______________________________________________________________________ -->
1040<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1041
1042<div class="doc_text">
1043 <table>
1044 <tbody>
1045 <tr><th>Type</th><th>Description</th></tr>
1046 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1047 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1048 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1049 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1050 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1051 </tbody>
1052 </table>
1053</div>
1054
1055<!-- _______________________________________________________________________ -->
1056<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1057
1058<div class="doc_text">
1059<h5>Overview:</h5>
1060<p>The void type does not represent any value and has no size.</p>
1061
1062<h5>Syntax:</h5>
1063
1064<pre>
1065 void
1066</pre>
1067</div>
1068
1069<!-- _______________________________________________________________________ -->
1070<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1071
1072<div class="doc_text">
1073<h5>Overview:</h5>
1074<p>The label type represents code labels.</p>
1075
1076<h5>Syntax:</h5>
1077
1078<pre>
1079 label
1080</pre>
1081</div>
1082
1083
1084<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1085<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1086
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1087<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1088
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1089<p>The real power in LLVM comes from the derived types in the system.
1090This is what allows a programmer to represent arrays, functions,
1091pointers, and other useful types. Note that these derived types may be
1092recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1093
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1094</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1095
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1096<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1097<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1098
1099<div class="doc_text">
1100
1101<h5>Overview:</h5>
1102<p>The integer type is a very simple derived type that simply specifies an
1103arbitrary bit width for the integer type desired. Any bit width from 1 bit to
11042^23-1 (about 8 million) can be specified.</p>
1105
1106<h5>Syntax:</h5>
1107
1108<pre>
1109 iN
1110</pre>
1111
1112<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1113value.</p>
1114
1115<h5>Examples:</h5>
1116<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1117 <tbody>
1118 <tr>
1119 <td><tt>i1</tt></td>
1120 <td>a single-bit integer.</td>
1121 </tr><tr>
1122 <td><tt>i32</tt></td>
1123 <td>a 32-bit integer.</td>
1124 </tr><tr>
1125 <td><tt>i1942652</tt></td>
1126 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1127 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1128 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1129</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1130</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1131
1132<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1133<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1134
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1135<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1136
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1137<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1138
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1139<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1140sequentially in memory. The array type requires a size (number of
1141elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1142
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1143<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1144
1145<pre>
1146 [&lt;# elements&gt; x &lt;elementtype&gt;]
1147</pre>
1148
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1149<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1150be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1151
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1152<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1153<table class="layout">
1154 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1155 <td class="left"><tt>[40 x i32]</tt></td>
1156 <td class="left">Array of 40 32-bit integer values.</td>
1157 </tr>
1158 <tr class="layout">
1159 <td class="left"><tt>[41 x i32]</tt></td>
1160 <td class="left">Array of 41 32-bit integer values.</td>
1161 </tr>
1162 <tr class="layout">
1163 <td class="left"><tt>[4 x i8]</tt></td>
1164 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1165 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1166</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1167<p>Here are some examples of multidimensional arrays:</p>
1168<table class="layout">
1169 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1170 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1171 <td class="left">3x4 array of 32-bit integer values.</td>
1172 </tr>
1173 <tr class="layout">
1174 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1175 <td class="left">12x10 array of single precision floating point values.</td>
1176 </tr>
1177 <tr class="layout">
1178 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1179 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1180 </tr>
1181</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1182
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1183<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1184length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1185LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1186As a special case, however, zero length arrays are recognized to be variable
1187length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1188type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1189
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1190</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1191
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1192<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1193<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1194<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1195<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1196<p>The function type can be thought of as a function signature. It
1197consists of a return type and a list of formal parameter types.
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1198Function types are usually used to build virtual function tables
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1199(which are structures of pointers to functions), for indirect function
1200calls, and when defining a function.</p>
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1201<p>
1202The return type of a function type cannot be an aggregate type.
1203</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1204<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1205<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1206<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukmanc24b7582004-08-12 20:16:08 +0000[diff] [blame]1207specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1208which indicates that the function takes a variable number of arguments.
1209Variable argument functions can access their arguments with the <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1210 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1211<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1212<table class="layout">
1213 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1214 <td class="left"><tt>i32 (i32)</tt></td>
1215 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1216 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1217 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1218 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1219 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1220 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1221 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1222 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1223 <tt>float</tt>.
1224 </td>
1225 </tr><tr class="layout">
1226 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1227 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1228 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1229 which returns an integer. This is the signature for <tt>printf</tt> in
1230 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1231 </td>
1232 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1233</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1234
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1235</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1236<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1237<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1238<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1239<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1240<p>The structure type is used to represent a collection of data members
1241together in memory. The packing of the field types is defined to match
1242the ABI of the underlying processor. The elements of a structure may
1243be any type that has a size.</p>
1244<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1245and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1246field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1247instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1248<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1249<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1250<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1251<table class="layout">
1252 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1253 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1254 <td class="left">A triple of three <tt>i32</tt> values</td>
1255 </tr><tr class="layout">
1256 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1257 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1258 second element is a <a href="#t_pointer">pointer</a> to a
1259 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1260 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1261 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1262</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1263</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1264
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1265<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1266<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1267</div>
1268<div class="doc_text">
1269<h5>Overview:</h5>
1270<p>The packed structure type is used to represent a collection of data members
1271together in memory. There is no padding between fields. Further, the alignment
1272of a packed structure is 1 byte. The elements of a packed structure may
1273be any type that has a size.</p>
1274<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1275and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1276field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1277instruction.</p>
1278<h5>Syntax:</h5>
1279<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1280<h5>Examples:</h5>
1281<table class="layout">
1282 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1283 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1284 <td class="left">A triple of three <tt>i32</tt> values</td>
1285 </tr><tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1286 <td class="left"><tt>&lt; { float, i32 (i32)* } &gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1287 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1288 second element is a <a href="#t_pointer">pointer</a> to a
1289 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1290 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1291 </tr>
1292</table>
1293</div>
1294
1295<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1296<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1297<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1298<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1299<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1300reference to another object, which must live in memory. Pointer types may have
1301an optional address space attribute defining the target-specific numbered
1302address space where the pointed-to object resides. The default address space is
1303zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1304<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1305<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1306<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1307<table class="layout">
1308 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1309 <td class="left"><tt>[4x i32]*</tt></td>
1310 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1311 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1312 </tr>
1313 <tr class="layout">
1314 <td class="left"><tt>i32 (i32 *) *</tt></td>
1315 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1316 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1317 <tt>i32</tt>.</td>
1318 </tr>
1319 <tr class="layout">
1320 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1321 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1322 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1323 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1324</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1325</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1326
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1327<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1328<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1329<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1330
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1331<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1332
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1333<p>A vector type is a simple derived type that represents a vector
1334of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1335are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1336A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1337elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1338of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1339considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1340
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1341<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1342
1343<pre>
1344 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1345</pre>
1346
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1347<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1348be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1349
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1350<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1351
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1352<table class="layout">
1353 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1354 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1355 <td class="left">Vector of 4 32-bit integer values.</td>
1356 </tr>
1357 <tr class="layout">
1358 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1359 <td class="left">Vector of 8 32-bit floating-point values.</td>
1360 </tr>
1361 <tr class="layout">
1362 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1363 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1364 </tr>
1365</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1366</div>
1367
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1368<!-- _______________________________________________________________________ -->
1369<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1370<div class="doc_text">
1371
1372<h5>Overview:</h5>
1373
1374<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1375corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1376In LLVM, opaque types can eventually be resolved to any type (not just a
1377structure type).</p>
1378
1379<h5>Syntax:</h5>
1380
1381<pre>
1382 opaque
1383</pre>
1384
1385<h5>Examples:</h5>
1386
1387<table class="layout">
1388 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1389 <td class="left"><tt>opaque</tt></td>
1390 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1391 </tr>
1392</table>
1393</div>
1394
1395
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1396<!-- *********************************************************************** -->
1397<div class="doc_section"> <a name="constants">Constants</a> </div>
1398<!-- *********************************************************************** -->
1399
1400<div class="doc_text">
1401
1402<p>LLVM has several different basic types of constants. This section describes
1403them all and their syntax.</p>
1404
1405</div>
1406
1407<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1408<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1409
1410<div class="doc_text">
1411
1412<dl>
1413 <dt><b>Boolean constants</b></dt>
1414
1415 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1416 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1417 </dd>
1418
1419 <dt><b>Integer constants</b></dt>
1420
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1421 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1422 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1423 integer types.
1424 </dd>
1425
1426 <dt><b>Floating point constants</b></dt>
1427
1428 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1429 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1430 notation (see below). Floating point constants must have a <a
1431 href="#t_floating">floating point</a> type. </dd>
1432
1433 <dt><b>Null pointer constants</b></dt>
1434
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1435 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1436 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1437
1438</dl>
1439
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1440<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1441of floating point constants. For example, the form '<tt>double
14420x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
14434.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1444(and the only time that they are generated by the disassembler) is when a
1445floating point constant must be emitted but it cannot be represented as a
1446decimal floating point number. For example, NaN's, infinities, and other
1447special values are represented in their IEEE hexadecimal format so that
1448assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1449
1450</div>
1451
1452<!-- ======================================================================= -->
1453<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1454</div>
1455
1456<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1457<p>Aggregate constants arise from aggregation of simple constants
1458and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1459
1460<dl>
1461 <dt><b>Structure constants</b></dt>
1462
1463 <dd>Structure constants are represented with notation similar to structure
1464 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner64910ee2007-12-25 20:34:52 +0000[diff] [blame]1465 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1466 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1467 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1468 types of elements must match those specified by the type.
1469 </dd>
1470
1471 <dt><b>Array constants</b></dt>
1472
1473 <dd>Array constants are represented with notation similar to array type
1474 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1475 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1476 constants must have <a href="#t_array">array type</a>, and the number and
1477 types of elements must match those specified by the type.
1478 </dd>
1479
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1480 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1481
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1482 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1483 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1484 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1485 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1486 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1487 match those specified by the type.
1488 </dd>
1489
1490 <dt><b>Zero initialization</b></dt>
1491
1492 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1493 value to zero of <em>any</em> type, including scalar and aggregate types.
1494 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1495 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1496 initializers.
1497 </dd>
1498</dl>
1499
1500</div>
1501
1502<!-- ======================================================================= -->
1503<div class="doc_subsection">
1504 <a name="globalconstants">Global Variable and Function Addresses</a>
1505</div>
1506
1507<div class="doc_text">
1508
1509<p>The addresses of <a href="#globalvars">global variables</a> and <a
1510href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1511constants. These constants are explicitly referenced when the <a
1512href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1513href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1514file:</p>
1515
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1516<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1517<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1518@X = global i32 17
1519@Y = global i32 42
1520@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1521</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1522</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1523
1524</div>
1525
1526<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1527<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1528<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1529 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1530 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1531 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1532
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1533 <p>Undefined values indicate to the compiler that the program is well defined
1534 no matter what value is used, giving the compiler more freedom to optimize.
1535 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1536</div>
1537
1538<!-- ======================================================================= -->
1539<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1540</div>
1541
1542<div class="doc_text">
1543
1544<p>Constant expressions are used to allow expressions involving other constants
1545to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1546href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1547that does not have side effects (e.g. load and call are not supported). The
1548following is the syntax for constant expressions:</p>
1549
1550<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1551 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1552 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1553 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1554
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1555 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1556 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1557 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1558
1559 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1560 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1561 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1562
1563 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1564 <dd>Truncate a floating point constant to another floating point type. The
1565 size of CST must be larger than the size of TYPE. Both types must be
1566 floating point.</dd>
1567
1568 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1569 <dd>Floating point extend a constant to another type. The size of CST must be
1570 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1571
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1572 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1573 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1574 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1575 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1576 of the same number of elements. If the value won't fit in the integer type,
1577 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1578
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1579 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1580 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1581 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1582 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1583 of the same number of elements. If the value won't fit in the integer type,
1584 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1585
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1586 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1587 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1588 constant. TYPE must be a scalar or vector floating point type. CST must be of
1589 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1590 of the same number of elements. If the value won't fit in the floating point
1591 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1592
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1593 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1594 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1595 constant. TYPE must be a scalar or vector floating point type. CST must be of
1596 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1597 of the same number of elements. If the value won't fit in the floating point
1598 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1599
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1600 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1601 <dd>Convert a pointer typed constant to the corresponding integer constant
1602 TYPE must be an integer type. CST must be of pointer type. The CST value is
1603 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1604
1605 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1606 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1607 pointer type. CST must be of integer type. The CST value is zero extended,
1608 truncated, or unchanged to make it fit in a pointer size. This one is
1609 <i>really</i> dangerous!</dd>
1610
1611 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1612 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1613 identical (same number of bits). The conversion is done as if the CST value
1614 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1615 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1616 vector types to any other type, as long as they have the same bit width. For
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1617 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1618 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1619
1620 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1621
1622 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1623 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1624 instruction, the index list may have zero or more indexes, which are required
1625 to make sense for the type of "CSTPTR".</dd>
1626
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1627 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1628
1629 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1630 constants.</dd>
1631
1632 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1633 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1634
1635 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1636 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1637
1638 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1639
1640 <dd>Perform the <a href="#i_extractelement">extractelement
1641 operation</a> on constants.
1642
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1643 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1644
1645 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1646 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1647
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1648
1649 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1650
1651 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1652 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1653
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1654 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1655
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1656 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1657 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1658 binary</a> operations. The constraints on operands are the same as those for
1659 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1660 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1661</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1662</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1663
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1664<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1665<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1666<!-- *********************************************************************** -->
1667
1668<!-- ======================================================================= -->
1669<div class="doc_subsection">
1670<a name="inlineasm">Inline Assembler Expressions</a>
1671</div>
1672
1673<div class="doc_text">
1674
1675<p>
1676LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1677Module-Level Inline Assembly</a>) through the use of a special value. This
1678value represents the inline assembler as a string (containing the instructions
1679to emit), a list of operand constraints (stored as a string), and a flag that
1680indicates whether or not the inline asm expression has side effects. An example
1681inline assembler expression is:
1682</p>
1683
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1684<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1685<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1686i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1687</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1688</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1689
1690<p>
1691Inline assembler expressions may <b>only</b> be used as the callee operand of
1692a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1693</p>
1694
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1695<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1696<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1697%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1698</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1699</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1700
1701<p>
1702Inline asms with side effects not visible in the constraint list must be marked
1703as having side effects. This is done through the use of the
1704'<tt>sideeffect</tt>' keyword, like so:
1705</p>
1706
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1707<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1708<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1709call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1710</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1711</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1712
1713<p>TODO: The format of the asm and constraints string still need to be
1714documented here. Constraints on what can be done (e.g. duplication, moving, etc
1715need to be documented).
1716</p>
1717
1718</div>
1719
1720<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1721<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1722<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1723
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1724<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1725
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1726<p>The LLVM instruction set consists of several different
1727classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1728instructions</a>, <a href="#binaryops">binary instructions</a>,
1729<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1730 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1731instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1732
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1733</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1734
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1735<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1736<div class="doc_subsection"> <a name="terminators">Terminator
1737Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1738
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1739<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1740
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1741<p>As mentioned <a href="#functionstructure">previously</a>, every
1742basic block in a program ends with a "Terminator" instruction, which
1743indicates which block should be executed after the current block is
1744finished. These terminator instructions typically yield a '<tt>void</tt>'
1745value: they produce control flow, not values (the one exception being
1746the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1747<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1748 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1749instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1750the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1751 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1752 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1753
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1754</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1755
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1756<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1757<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1758Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1759<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1760<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1761<pre> ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1762 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1763</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1764<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1765<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1766value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1767<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1768returns a value and then causes control flow, and one that just causes
1769control flow to occur.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1770<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1771<p>The '<tt>ret</tt>' instruction may return any '<a
1772 href="#t_firstclass">first class</a>' type. Notice that a function is
1773not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1774instruction inside of the function that returns a value that does not
1775match the return type of the function.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1776<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1777<p>When the '<tt>ret</tt>' instruction is executed, control flow
1778returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1779 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1780the instruction after the call. If the caller was an "<a
1781 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1782at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1783returns a value, that value shall set the call or invoke instruction's
1784return value.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1785<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1786<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1787 ret void <i>; Return from a void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1788</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1789</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1790<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1791<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1792<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1793<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1794<pre> br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1795</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1796<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1797<p>The '<tt>br</tt>' instruction is used to cause control flow to
1798transfer to a different basic block in the current function. There are
1799two forms of this instruction, corresponding to a conditional branch
1800and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1801<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1802<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1803single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1804unconditional form of the '<tt>br</tt>' instruction takes a single
1805'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1806<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1807<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1808argument is evaluated. If the value is <tt>true</tt>, control flows
1809to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1810control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1811<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1812<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1813 href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1814</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1815<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1816<div class="doc_subsubsection">
1817 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1818</div>
1819
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1820<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1821<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1822
1823<pre>
1824 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1825</pre>
1826
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1827<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1828
1829<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1830several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1831instruction, allowing a branch to occur to one of many possible
1832destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1833
1834
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1835<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1836
1837<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1838comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1839an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1840table is not allowed to contain duplicate constant entries.</p>
1841
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1842<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1843
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1844<p>The <tt>switch</tt> instruction specifies a table of values and
1845destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1846table is searched for the given value. If the value is found, control flow is
1847transfered to the corresponding destination; otherwise, control flow is
1848transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1849
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1850<h5>Implementation:</h5>
1851
1852<p>Depending on properties of the target machine and the particular
1853<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1854ways. For example, it could be generated as a series of chained conditional
1855branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1856
1857<h5>Example:</h5>
1858
1859<pre>
1860 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1861 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1862 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1863
1864 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1865 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1866
1867 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1868 switch i32 %val, label %otherwise [ i32 0, label %onzero
1869 i32 1, label %onone
1870 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1871</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1872</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1873
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1874<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1875<div class="doc_subsubsection">
1876 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1877</div>
1878
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1879<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1880
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1881<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1882
1883<pre>
1884 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] &lt;ptr to function ty&gt; %&lt;function ptr val&gt;(&lt;function args&gt;)
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]1885 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1886</pre>
1887
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]1888<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1889
1890<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1891function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1892'<tt>normal</tt>' label or the
1893'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1894"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1895"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1896href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1897continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1898
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1899<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1900
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1901<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1902
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1903<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1904 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]1905 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1906 convention</a> the call should use. If none is specified, the call defaults
1907 to using C calling conventions.
1908 </li>
1909 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1910 function value being invoked. In most cases, this is a direct function
1911 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1912 an arbitrary pointer to function value.
1913 </li>
1914
1915 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1916 function to be invoked. </li>
1917
1918 <li>'<tt>function args</tt>': argument list whose types match the function
1919 signature argument types. If the function signature indicates the function
1920 accepts a variable number of arguments, the extra arguments can be
1921 specified. </li>
1922
1923 <li>'<tt>normal label</tt>': the label reached when the called function
1924 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1925
1926 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1927 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1928
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1929</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1930
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1931<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1932
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1933<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1934href="#i_call">call</a></tt>' instruction in most regards. The primary
1935difference is that it establishes an association with a label, which is used by
1936the runtime library to unwind the stack.</p>
1937
1938<p>This instruction is used in languages with destructors to ensure that proper
1939cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1940exception. Additionally, this is important for implementation of
1941'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1942
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1943<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1944<pre>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1945 %retval = invoke i32 %Test(i32 15) to label %Continue
1946 unwind label %TestCleanup <i>; {i32}:retval set</i>
1947 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1948 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1949</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1950</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1951
1952
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1953<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1954
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1955<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1956Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1957
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1958<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1959
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1960<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1961<pre>
1962 unwind
1963</pre>
1964
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1965<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1966
1967<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1968at the first callee in the dynamic call stack which used an <a
1969href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1970primarily used to implement exception handling.</p>
1971
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1972<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1973
1974<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1975immediately halt. The dynamic call stack is then searched for the first <a
1976href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1977execution continues at the "exceptional" destination block specified by the
1978<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1979dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1980</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1981
1982<!-- _______________________________________________________________________ -->
1983
1984<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1985Instruction</a> </div>
1986
1987<div class="doc_text">
1988
1989<h5>Syntax:</h5>
1990<pre>
1991 unreachable
1992</pre>
1993
1994<h5>Overview:</h5>
1995
1996<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1997instruction is used to inform the optimizer that a particular portion of the
1998code is not reachable. This can be used to indicate that the code after a
1999no-return function cannot be reached, and other facts.</p>
2000
2001<h5>Semantics:</h5>
2002
2003<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2004</div>
2005
2006
2007
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2008<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2009<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2010<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2011<p>Binary operators are used to do most of the computation in a
2012program. They require two operands, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2013produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2014multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2015The result value of a binary operator is not
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2016necessarily the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2017<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2018</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2019<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2020<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
2021Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2022<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2023<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2024<pre> &lt;result&gt; = add &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2025</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2026<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2027<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2028<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2029<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2030 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2031 This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2032Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2033<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2034<p>The value produced is the integer or floating point sum of the two
2035operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2036<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2037<pre> &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2038</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2039</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2040<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2041<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
2042Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2043<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2044<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2045<pre> &lt;result&gt; = sub &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2046</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2047<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2048<p>The '<tt>sub</tt>' instruction returns the difference of its two
2049operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2050<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
2051instruction present in most other intermediate representations.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2052<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2053<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2054 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2055values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2056This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2057Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2058<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2059<p>The value produced is the integer or floating point difference of
2060the two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2061<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2062<pre>
2063 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2064 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2065</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2066</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2067<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2068<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2069Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2070<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2071<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2072<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2073</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2074<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2075<p>The '<tt>mul</tt>' instruction returns the product of its two
2076operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2077<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2078<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2079 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2080values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2081This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2082Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2083<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2084<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2085two operands.</p>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]2086<p>Because the operands are the same width, the result of an integer
2087multiplication is the same whether the operands should be deemed unsigned or
2088signed.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2089<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2090<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2091</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2092</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2093<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2094<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2095</a></div>
2096<div class="doc_text">
2097<h5>Syntax:</h5>
2098<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2099</pre>
2100<h5>Overview:</h5>
2101<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2102operands.</p>
2103<h5>Arguments:</h5>
2104<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2105<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2106types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2107of the values in which case the elements must be integers.</p>
2108<h5>Semantics:</h5>
2109<p>The value produced is the unsigned integer quotient of the two operands. This
2110instruction always performs an unsigned division operation, regardless of
2111whether the arguments are unsigned or not.</p>
2112<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2113<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2114</pre>
2115</div>
2116<!-- _______________________________________________________________________ -->
2117<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2118</a> </div>
2119<div class="doc_text">
2120<h5>Syntax:</h5>
2121<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2122</pre>
2123<h5>Overview:</h5>
2124<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2125operands.</p>
2126<h5>Arguments:</h5>
2127<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2128<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2129types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2130of the values in which case the elements must be integers.</p>
2131<h5>Semantics:</h5>
2132<p>The value produced is the signed integer quotient of the two operands. This
2133instruction always performs a signed division operation, regardless of whether
2134the arguments are signed or not.</p>
2135<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2136<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2137</pre>
2138</div>
2139<!-- _______________________________________________________________________ -->
2140<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2141Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2142<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2143<h5>Syntax:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2144<pre> &lt;result&gt; = fdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2145</pre>
2146<h5>Overview:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2147<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2148operands.</p>
2149<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2150<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2151<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2152identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2153versions of floating point values.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2154<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2155<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2156<h5>Example:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2157<pre> &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2158</pre>
2159</div>
2160<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2161<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2162</div>
2163<div class="doc_text">
2164<h5>Syntax:</h5>
2165<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2166</pre>
2167<h5>Overview:</h5>
2168<p>The '<tt>urem</tt>' instruction returns the remainder from the
2169unsigned division of its two arguments.</p>
2170<h5>Arguments:</h5>
2171<p>The two arguments to the '<tt>urem</tt>' instruction must be
2172<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2173types. This instruction can also take <a href="#t_vector">vector</a> versions
2174of the values in which case the elements must be integers.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2175<h5>Semantics:</h5>
2176<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2177This instruction always performs an unsigned division to get the remainder,
2178regardless of whether the arguments are unsigned or not.</p>
2179<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2180<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2181</pre>
2182
2183</div>
2184<!-- _______________________________________________________________________ -->
2185<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2186Instruction</a> </div>
2187<div class="doc_text">
2188<h5>Syntax:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2189<pre> &lt;result&gt; = srem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2190</pre>
2191<h5>Overview:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2192<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2193signed division of its two operands. This instruction can also take
2194<a href="#t_vector">vector</a> versions of the values in which case
2195the elements must be integers.</p>
2196</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2197<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2198<p>The two arguments to the '<tt>srem</tt>' instruction must be
2199<a href="#t_integer">integer</a> values. Both arguments must have identical
2200types.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2201<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2202<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2203has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2204operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2205a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2206 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2207Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2208please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2209Wikipedia: modulo operation</a>.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2210<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2211<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2212</pre>
2213
2214</div>
2215<!-- _______________________________________________________________________ -->
2216<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2217Instruction</a> </div>
2218<div class="doc_text">
2219<h5>Syntax:</h5>
2220<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2221</pre>
2222<h5>Overview:</h5>
2223<p>The '<tt>frem</tt>' instruction returns the remainder from the
2224division of its two operands.</p>
2225<h5>Arguments:</h5>
2226<p>The two arguments to the '<tt>frem</tt>' instruction must be
2227<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2228identical types. This instruction can also take <a href="#t_vector">vector</a>
2229versions of floating point values.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2230<h5>Semantics:</h5>
2231<p>This instruction returns the <i>remainder</i> of a division.</p>
2232<h5>Example:</h5>
2233<pre> &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2234</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2235</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2236
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2237<!-- ======================================================================= -->
2238<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2239Operations</a> </div>
2240<div class="doc_text">
2241<p>Bitwise binary operators are used to do various forms of
2242bit-twiddling in a program. They are generally very efficient
2243instructions and can commonly be strength reduced from other
2244instructions. They require two operands, execute an operation on them,
2245and produce a single value. The resulting value of the bitwise binary
2246operators is always the same type as its first operand.</p>
2247</div>
2248
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2249<!-- _______________________________________________________________________ -->
2250<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2251Instruction</a> </div>
2252<div class="doc_text">
2253<h5>Syntax:</h5>
2254<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2255</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2256
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2257<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2258
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2259<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2260the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2261
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2262<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2263
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2264<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2265 href="#t_integer">integer</a> type.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2266
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2267<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2268
2269<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2270<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2271of bits in <tt>var1</tt>, the result is undefined.</p>
2272
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2273<h5>Example:</h5><pre>
2274 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2275 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2276 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2277 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2278</pre>
2279</div>
2280<!-- _______________________________________________________________________ -->
2281<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2282Instruction</a> </div>
2283<div class="doc_text">
2284<h5>Syntax:</h5>
2285<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2286</pre>
2287
2288<h5>Overview:</h5>
2289<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2290operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2291
2292<h5>Arguments:</h5>
2293<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2294<a href="#t_integer">integer</a> type.</p>
2295
2296<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2297
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2298<p>This instruction always performs a logical shift right operation. The most
2299significant bits of the result will be filled with zero bits after the
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2300shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2301the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2302
2303<h5>Example:</h5>
2304<pre>
2305 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2306 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2307 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2308 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2309 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2310</pre>
2311</div>
2312
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2313<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2314<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2315Instruction</a> </div>
2316<div class="doc_text">
2317
2318<h5>Syntax:</h5>
2319<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2320</pre>
2321
2322<h5>Overview:</h5>
2323<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2324operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2325
2326<h5>Arguments:</h5>
2327<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2328<a href="#t_integer">integer</a> type.</p>
2329
2330<h5>Semantics:</h5>
2331<p>This instruction always performs an arithmetic shift right operation,
2332The most significant bits of the result will be filled with the sign bit
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2333of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2334larger than the number of bits in <tt>var1</tt>, the result is undefined.
2335</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2336
2337<h5>Example:</h5>
2338<pre>
2339 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2340 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2341 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2342 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2343 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2344</pre>
2345</div>
2346
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2347<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2348<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2349Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2350<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2351<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2352<pre> &lt;result&gt; = and &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2353</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2354<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2355<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2356its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2357<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2358<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2359 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2360identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2361<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2362<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2363<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2364<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2365<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2366 <tbody>
2367 <tr>
2368 <td>In0</td>
2369 <td>In1</td>
2370 <td>Out</td>
2371 </tr>
2372 <tr>
2373 <td>0</td>
2374 <td>0</td>
2375 <td>0</td>
2376 </tr>
2377 <tr>
2378 <td>0</td>
2379 <td>1</td>
2380 <td>0</td>
2381 </tr>
2382 <tr>
2383 <td>1</td>
2384 <td>0</td>
2385 <td>0</td>
2386 </tr>
2387 <tr>
2388 <td>1</td>
2389 <td>1</td>
2390 <td>1</td>
2391 </tr>
2392 </tbody>
2393</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2394</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2395<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2396<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2397 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2398 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2399</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2400</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2401<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2402<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2403<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2404<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2405<pre> &lt;result&gt; = or &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2406</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2407<h5>Overview:</h5>
2408<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2409or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2410<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2411<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2412 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2413identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2414<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2415<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2416<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2417<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2418<table border="1" cellspacing="0" cellpadding="4">
2419 <tbody>
2420 <tr>
2421 <td>In0</td>
2422 <td>In1</td>
2423 <td>Out</td>
2424 </tr>
2425 <tr>
2426 <td>0</td>
2427 <td>0</td>
2428 <td>0</td>
2429 </tr>
2430 <tr>
2431 <td>0</td>
2432 <td>1</td>
2433 <td>1</td>
2434 </tr>
2435 <tr>
2436 <td>1</td>
2437 <td>0</td>
2438 <td>1</td>
2439 </tr>
2440 <tr>
2441 <td>1</td>
2442 <td>1</td>
2443 <td>1</td>
2444 </tr>
2445 </tbody>
2446</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2447</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2448<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2449<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2450 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2451 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2452</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2453</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2454<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2455<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2456Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2457<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2458<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2459<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2460</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2461<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2462<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2463or of its two operands. The <tt>xor</tt> is used to implement the
2464"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2465<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2466<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2467 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2468identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2469<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2470<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2471<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2472<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2473<table border="1" cellspacing="0" cellpadding="4">
2474 <tbody>
2475 <tr>
2476 <td>In0</td>
2477 <td>In1</td>
2478 <td>Out</td>
2479 </tr>
2480 <tr>
2481 <td>0</td>
2482 <td>0</td>
2483 <td>0</td>
2484 </tr>
2485 <tr>
2486 <td>0</td>
2487 <td>1</td>
2488 <td>1</td>
2489 </tr>
2490 <tr>
2491 <td>1</td>
2492 <td>0</td>
2493 <td>1</td>
2494 </tr>
2495 <tr>
2496 <td>1</td>
2497 <td>1</td>
2498 <td>0</td>
2499 </tr>
2500 </tbody>
2501</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2502</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2503<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2504<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2505<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2506 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2507 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2508 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2509</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2510</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2511
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2512<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2513<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2514 <a name="vectorops">Vector Operations</a>
2515</div>
2516
2517<div class="doc_text">
2518
2519<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2520target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2521vector-specific operations needed to process vectors effectively. While LLVM
2522does directly support these vector operations, many sophisticated algorithms
2523will want to use target-specific intrinsics to take full advantage of a specific
2524target.</p>
2525
2526</div>
2527
2528<!-- _______________________________________________________________________ -->
2529<div class="doc_subsubsection">
2530 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2531</div>
2532
2533<div class="doc_text">
2534
2535<h5>Syntax:</h5>
2536
2537<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2538 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2539</pre>
2540
2541<h5>Overview:</h5>
2542
2543<p>
2544The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2545element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2546</p>
2547
2548
2549<h5>Arguments:</h5>
2550
2551<p>
2552The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2553value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2554an index indicating the position from which to extract the element.
2555The index may be a variable.</p>
2556
2557<h5>Semantics:</h5>
2558
2559<p>
2560The result is a scalar of the same type as the element type of
2561<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2562<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2563results are undefined.
2564</p>
2565
2566<h5>Example:</h5>
2567
2568<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2569 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2570</pre>
2571</div>
2572
2573
2574<!-- _______________________________________________________________________ -->
2575<div class="doc_subsubsection">
2576 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2577</div>
2578
2579<div class="doc_text">
2580
2581<h5>Syntax:</h5>
2582
2583<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2584 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2585</pre>
2586
2587<h5>Overview:</h5>
2588
2589<p>
2590The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2591element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2592</p>
2593
2594
2595<h5>Arguments:</h5>
2596
2597<p>
2598The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2599value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2600scalar value whose type must equal the element type of the first
2601operand. The third operand is an index indicating the position at
2602which to insert the value. The index may be a variable.</p>
2603
2604<h5>Semantics:</h5>
2605
2606<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2607The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2608element values are those of <tt>val</tt> except at position
2609<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2610exceeds the length of <tt>val</tt>, the results are undefined.
2611</p>
2612
2613<h5>Example:</h5>
2614
2615<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2616 %result = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2617</pre>
2618</div>
2619
2620<!-- _______________________________________________________________________ -->
2621<div class="doc_subsubsection">
2622 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2623</div>
2624
2625<div class="doc_text">
2626
2627<h5>Syntax:</h5>
2628
2629<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2630 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;n x i32&gt; &lt;mask&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2631</pre>
2632
2633<h5>Overview:</h5>
2634
2635<p>
2636The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2637from two input vectors, returning a vector of the same type.
2638</p>
2639
2640<h5>Arguments:</h5>
2641
2642<p>
2643The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2644with types that match each other and types that match the result of the
2645instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2646of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2647</p>
2648
2649<p>
2650The shuffle mask operand is required to be a constant vector with either
2651constant integer or undef values.
2652</p>
2653
2654<h5>Semantics:</h5>
2655
2656<p>
2657The elements of the two input vectors are numbered from left to right across
2658both of the vectors. The shuffle mask operand specifies, for each element of
2659the result vector, which element of the two input registers the result element
2660gets. The element selector may be undef (meaning "don't care") and the second
2661operand may be undef if performing a shuffle from only one vector.
2662</p>
2663
2664<h5>Example:</h5>
2665
2666<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2667 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2668 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2669 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2670 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2671</pre>
2672</div>
2673
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2674
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2675<!-- ======================================================================= -->
2676<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2677 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2678</div>
2679
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2680<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2681
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2682<p>A key design point of an SSA-based representation is how it
2683represents memory. In LLVM, no memory locations are in SSA form, which
2684makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2685allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2686
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2687</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2688
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2689<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2690<div class="doc_subsubsection">
2691 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2692</div>
2693
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2694<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2695
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2696<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2697
2698<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2699 &lt;result&gt; = malloc &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2700</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2701
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2702<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2703
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2704<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]2705heap and returns a pointer to it. The object is always allocated in the generic
2706address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2707
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2708<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2709
2710<p>The '<tt>malloc</tt>' instruction allocates
2711<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]2712bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2713appropriate type to the program. If "NumElements" is specified, it is the
2714number of elements allocated. If an alignment is specified, the value result
2715of the allocation is guaranteed to be aligned to at least that boundary. If
2716not specified, or if zero, the target can choose to align the allocation on any
2717convenient boundary.</p>
2718
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2719<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2720
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2721<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2722
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2723<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2724a pointer is returned.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2725
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2726<h5>Example:</h5>
2727
2728<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2729 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2730
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2731 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2732 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2733 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2734 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2735 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2736</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2737</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2738
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2739<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2740<div class="doc_subsubsection">
2741 <a name="i_free">'<tt>free</tt>' Instruction</a>
2742</div>
2743
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2744<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2745
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2746<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2747
2748<pre>
2749 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2750</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2751
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2752<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2753
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2754<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2755memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2756
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2757<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2758
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2759<p>'<tt>value</tt>' shall be a pointer value that points to a value
2760that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2761instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2762
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2763<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2764
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2765<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2766after this instruction executes.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2767
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2768<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2769
2770<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2771 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2772 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2773</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2774</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2775
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2776<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2777<div class="doc_subsubsection">
2778 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2779</div>
2780
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2781<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2782
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2783<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2784
2785<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2786 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2787</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2788
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2789<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2790
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2791<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2792currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]2793returns to its caller. The object is always allocated in the generic address
2794space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2795
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2796<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2797
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2798<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2799bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2800appropriate type to the program. If "NumElements" is specified, it is the
2801number of elements allocated. If an alignment is specified, the value result
2802of the allocation is guaranteed to be aligned to at least that boundary. If
2803not specified, or if zero, the target can choose to align the allocation on any
2804convenient boundary.</p>
2805
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2806<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2807
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2808<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2809
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2810<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2811memory is automatically released when the function returns. The '<tt>alloca</tt>'
2812instruction is commonly used to represent automatic variables that must
2813have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]2814 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2815instructions), the memory is reclaimed.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2816
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2817<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2818
2819<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2820 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2821 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2822 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2823 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2824</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2825</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2826
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2827<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2828<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2829Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2830<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2831<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2832<pre> &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br> &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br></pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2833<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2834<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2835<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2836<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2837address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]2838 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2839marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2840the number or order of execution of this <tt>load</tt> with other
2841volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2842instructions. </p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2843<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2844<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2845<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2846<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2847 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2848 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2849 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2850</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2851</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2852<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2853<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2854Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]2855<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2856<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2857<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2858 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2859</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2860<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2861<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2862<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2863<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2864to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2865operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2866operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2867optimizer is not allowed to modify the number or order of execution of
2868this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2869 href="#i_store">store</a></tt> instructions.</p>
2870<h5>Semantics:</h5>
2871<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2872at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2873<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2874<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]2875 store i32 3, i32* %ptr <i>; yields {void}</i>
2876 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2877</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2878</div>
2879
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2880<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2881<div class="doc_subsubsection">
2882 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2883</div>
2884
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2885<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2886<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2887<pre>
2888 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2889</pre>
2890
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2891<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2892
2893<p>
2894The '<tt>getelementptr</tt>' instruction is used to get the address of a
2895subelement of an aggregate data structure.</p>
2896
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2897<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2898
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2899<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2900elements of the aggregate object to index to. The actual types of the arguments
2901provided depend on the type of the first pointer argument. The
2902'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]2903levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2904structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2905into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2906be sign extended to 64-bit values.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2907
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2908<p>For example, let's consider a C code fragment and how it gets
2909compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2910
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2911<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2912<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2913struct RT {
2914 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2915 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2916 char C;
2917};
2918struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2919 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2920 double Y;
2921 struct RT Z;
2922};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2923
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2924int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2925 return &amp;s[1].Z.B[5][13];
2926}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2927</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2928</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2929
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2930<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2931
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2932<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2933<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2934%RT = type { i8 , [10 x [20 x i32]], i8 }
2935%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2936
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2937define i32* %foo(%ST* %s) {
2938entry:
2939 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2940 ret i32* %reg
2941}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2942</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2943</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2944
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2945<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2946
2947<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2948on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2949and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2950<a href="#t_integer">integer</a> type but the value will always be sign extended
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2951to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2952<b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2953
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2954<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2955type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2956}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2957the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2958i8 }</tt>' type, another structure. The third index indexes into the second
2959element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2960array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2961'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2962to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2963
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2964<p>Note that it is perfectly legal to index partially through a
2965structure, returning a pointer to an inner element. Because of this,
2966the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2967
2968<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2969 define i32* %foo(%ST* %s) {
2970 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2971 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2972 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2973 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2974 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2975 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2976 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2977</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2978
2979<p>Note that it is undefined to access an array out of bounds: array and
2980pointer indexes must always be within the defined bounds of the array type.
2981The one exception for this rules is zero length arrays. These arrays are
2982defined to be accessible as variable length arrays, which requires access
2983beyond the zero'th element.</p>
2984
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2985<p>The getelementptr instruction is often confusing. For some more insight
2986into how it works, see <a href="GetElementPtr.html">the getelementptr
2987FAQ</a>.</p>
2988
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2989<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2990
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2991<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2992 <i>; yields [12 x i8]*:aptr</i>
2993 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2994</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2995</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2996
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2997<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2998<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2999</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3000<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3001<p>The instructions in this category are the conversion instructions (casting)
3002which all take a single operand and a type. They perform various bit conversions
3003on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3004</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3005
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3006<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3007<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3008 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3009</div>
3010<div class="doc_text">
3011
3012<h5>Syntax:</h5>
3013<pre>
3014 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3015</pre>
3016
3017<h5>Overview:</h5>
3018<p>
3019The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3020</p>
3021
3022<h5>Arguments:</h5>
3023<p>
3024The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3025be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3026and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3027type. The bit size of <tt>value</tt> must be larger than the bit size of
3028<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3029
3030<h5>Semantics:</h5>
3031<p>
3032The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3033and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3034larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3035It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3036
3037<h5>Example:</h5>
3038<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3039 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3040 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3041 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3042</pre>
3043</div>
3044
3045<!-- _______________________________________________________________________ -->
3046<div class="doc_subsubsection">
3047 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3048</div>
3049<div class="doc_text">
3050
3051<h5>Syntax:</h5>
3052<pre>
3053 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3054</pre>
3055
3056<h5>Overview:</h5>
3057<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3058<tt>ty2</tt>.</p>
3059
3060
3061<h5>Arguments:</h5>
3062<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3063<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3064also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3065<tt>value</tt> must be smaller than the bit size of the destination type,
3066<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3067
3068<h5>Semantics:</h5>
3069<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3070bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3071
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3072<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3073
3074<h5>Example:</h5>
3075<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3076 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3077 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3078</pre>
3079</div>
3080
3081<!-- _______________________________________________________________________ -->
3082<div class="doc_subsubsection">
3083 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3084</div>
3085<div class="doc_text">
3086
3087<h5>Syntax:</h5>
3088<pre>
3089 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3090</pre>
3091
3092<h5>Overview:</h5>
3093<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3094
3095<h5>Arguments:</h5>
3096<p>
3097The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3098<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3099also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3100<tt>value</tt> must be smaller than the bit size of the destination type,
3101<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3102
3103<h5>Semantics:</h5>
3104<p>
3105The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3106bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3107the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3108
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3109<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3110
3111<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3112<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3113 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3114 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3115</pre>
3116</div>
3117
3118<!-- _______________________________________________________________________ -->
3119<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3120 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3121</div>
3122
3123<div class="doc_text">
3124
3125<h5>Syntax:</h5>
3126
3127<pre>
3128 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3129</pre>
3130
3131<h5>Overview:</h5>
3132<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3133<tt>ty2</tt>.</p>
3134
3135
3136<h5>Arguments:</h5>
3137<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3138 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3139cast it to. The size of <tt>value</tt> must be larger than the size of
3140<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3141<i>no-op cast</i>.</p>
3142
3143<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3144<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3145<a href="#t_floating">floating point</a> type to a smaller
3146<a href="#t_floating">floating point</a> type. If the value cannot fit within
3147the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3148
3149<h5>Example:</h5>
3150<pre>
3151 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3152 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3153</pre>
3154</div>
3155
3156<!-- _______________________________________________________________________ -->
3157<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3158 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3159</div>
3160<div class="doc_text">
3161
3162<h5>Syntax:</h5>
3163<pre>
3164 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3165</pre>
3166
3167<h5>Overview:</h5>
3168<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3169floating point value.</p>
3170
3171<h5>Arguments:</h5>
3172<p>The '<tt>fpext</tt>' instruction takes a
3173<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3174and a <a href="#t_floating">floating point</a> type to cast it to. The source
3175type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3176
3177<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3178<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3179<a href="#t_floating">floating point</a> type to a larger
3180<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3181used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3182<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3183
3184<h5>Example:</h5>
3185<pre>
3186 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3187 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3188</pre>
3189</div>
3190
3191<!-- _______________________________________________________________________ -->
3192<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3193 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3194</div>
3195<div class="doc_text">
3196
3197<h5>Syntax:</h5>
3198<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3199 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3200</pre>
3201
3202<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3203<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3204unsigned integer equivalent of type <tt>ty2</tt>.
3205</p>
3206
3207<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3208<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3209scalar or vector <a href="#t_floating">floating point</a> value, and a type
3210to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3211type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3212vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3213
3214<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3215<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3216<a href="#t_floating">floating point</a> operand into the nearest (rounding
3217towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3218the results are undefined.</p>
3219
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3220<h5>Example:</h5>
3221<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3222 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3223 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3224 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3225</pre>
3226</div>
3227
3228<!-- _______________________________________________________________________ -->
3229<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3230 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3231</div>
3232<div class="doc_text">
3233
3234<h5>Syntax:</h5>
3235<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3236 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3237</pre>
3238
3239<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3240<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3241<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3242</p>
3243
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3244<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3245<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3246scalar or vector <a href="#t_floating">floating point</a> value, and a type
3247to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3248type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3249vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3250
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3251<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3252<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3253<a href="#t_floating">floating point</a> operand into the nearest (rounding
3254towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3255the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3256
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3257<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3258<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3259 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3260 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3261 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3262</pre>
3263</div>
3264
3265<!-- _______________________________________________________________________ -->
3266<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3267 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3268</div>
3269<div class="doc_text">
3270
3271<h5>Syntax:</h5>
3272<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3273 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3274</pre>
3275
3276<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3277<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3278integer and converts that value to the <tt>ty2</tt> type.</p>
3279
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3280<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3281<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3282scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3283to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3284type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3285floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3286
3287<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3288<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3289integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3290the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3291
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3292<h5>Example:</h5>
3293<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3294 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3295 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3296</pre>
3297</div>
3298
3299<!-- _______________________________________________________________________ -->
3300<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3301 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3302</div>
3303<div class="doc_text">
3304
3305<h5>Syntax:</h5>
3306<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3307 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3308</pre>
3309
3310<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3311<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3312integer and converts that value to the <tt>ty2</tt> type.</p>
3313
3314<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3315<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3316scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3317to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3318type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3319floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3320
3321<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3322<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3323integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3324the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3325
3326<h5>Example:</h5>
3327<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3328 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3329 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3330</pre>
3331</div>
3332
3333<!-- _______________________________________________________________________ -->
3334<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3335 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3336</div>
3337<div class="doc_text">
3338
3339<h5>Syntax:</h5>
3340<pre>
3341 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3342</pre>
3343
3344<h5>Overview:</h5>
3345<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3346the integer type <tt>ty2</tt>.</p>
3347
3348<h5>Arguments:</h5>
3349<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3350must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3351<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3352
3353<h5>Semantics:</h5>
3354<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3355<tt>ty2</tt> by interpreting the pointer value as an integer and either
3356truncating or zero extending that value to the size of the integer type. If
3357<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3358<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3359are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3360change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3361
3362<h5>Example:</h5>
3363<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3364 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3365 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3366</pre>
3367</div>
3368
3369<!-- _______________________________________________________________________ -->
3370<div class="doc_subsubsection">
3371 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3372</div>
3373<div class="doc_text">
3374
3375<h5>Syntax:</h5>
3376<pre>
3377 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3378</pre>
3379
3380<h5>Overview:</h5>
3381<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3382a pointer type, <tt>ty2</tt>.</p>
3383
3384<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3385<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3386value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3387<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3388
3389<h5>Semantics:</h5>
3390<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3391<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3392the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3393size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3394the size of a pointer then a zero extension is done. If they are the same size,
3395nothing is done (<i>no-op cast</i>).</p>
3396
3397<h5>Example:</h5>
3398<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3399 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3400 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3401 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3402</pre>
3403</div>
3404
3405<!-- _______________________________________________________________________ -->
3406<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3407 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3408</div>
3409<div class="doc_text">
3410
3411<h5>Syntax:</h5>
3412<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3413 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3414</pre>
3415
3416<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3417<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3418<tt>ty2</tt> without changing any bits.</p>
3419
3420<h5>Arguments:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3421<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3422a first class value, and a type to cast it to, which must also be a <a
3423 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3424and the destination type, <tt>ty2</tt>, must be identical. If the source
3425type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3426
3427<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3428<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3429<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3430this conversion. The conversion is done as if the <tt>value</tt> had been
3431stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3432converted to other pointer types with this instruction. To convert pointers to
3433other types, use the <a href="#i_inttoptr">inttoptr</a> or
3434<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3435
3436<h5>Example:</h5>
3437<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3438 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3439 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3440 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3441</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3442</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3443
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3444<!-- ======================================================================= -->
3445<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3446<div class="doc_text">
3447<p>The instructions in this category are the "miscellaneous"
3448instructions, which defy better classification.</p>
3449</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3450
3451<!-- _______________________________________________________________________ -->
3452<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3453</div>
3454<div class="doc_text">
3455<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3456<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3457</pre>
3458<h5>Overview:</h5>
3459<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3460of its two integer operands.</p>
3461<h5>Arguments:</h5>
3462<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3463the condition code indicating the kind of comparison to perform. It is not
3464a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3465<ol>
3466 <li><tt>eq</tt>: equal</li>
3467 <li><tt>ne</tt>: not equal </li>
3468 <li><tt>ugt</tt>: unsigned greater than</li>
3469 <li><tt>uge</tt>: unsigned greater or equal</li>
3470 <li><tt>ult</tt>: unsigned less than</li>
3471 <li><tt>ule</tt>: unsigned less or equal</li>
3472 <li><tt>sgt</tt>: signed greater than</li>
3473 <li><tt>sge</tt>: signed greater or equal</li>
3474 <li><tt>slt</tt>: signed less than</li>
3475 <li><tt>sle</tt>: signed less or equal</li>
3476</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3477<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3478<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3479<h5>Semantics:</h5>
3480<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3481the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3482yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3483<ol>
3484 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3485 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3486 </li>
3487 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3488 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3489 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3490 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3491 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3492 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3493 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3494 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3495 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3496 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3497 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3498 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3499 <li><tt>sge</tt>: interprets the operands as signed values and yields
3500 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3501 <li><tt>slt</tt>: interprets the operands as signed values and yields
3502 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3503 <li><tt>sle</tt>: interprets the operands as signed values and yields
3504 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3505</ol>
3506<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3507values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3508
3509<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3510<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3511 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3512 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3513 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3514 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3515 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3516</pre>
3517</div>
3518
3519<!-- _______________________________________________________________________ -->
3520<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3521</div>
3522<div class="doc_text">
3523<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3524<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3525</pre>
3526<h5>Overview:</h5>
3527<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3528of its floating point operands.</p>
3529<h5>Arguments:</h5>
3530<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3531the condition code indicating the kind of comparison to perform. It is not
3532a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3533<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3534 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3535 <li><tt>oeq</tt>: ordered and equal</li>
3536 <li><tt>ogt</tt>: ordered and greater than </li>
3537 <li><tt>oge</tt>: ordered and greater than or equal</li>
3538 <li><tt>olt</tt>: ordered and less than </li>
3539 <li><tt>ole</tt>: ordered and less than or equal</li>
3540 <li><tt>one</tt>: ordered and not equal</li>
3541 <li><tt>ord</tt>: ordered (no nans)</li>
3542 <li><tt>ueq</tt>: unordered or equal</li>
3543 <li><tt>ugt</tt>: unordered or greater than </li>
3544 <li><tt>uge</tt>: unordered or greater than or equal</li>
3545 <li><tt>ult</tt>: unordered or less than </li>
3546 <li><tt>ule</tt>: unordered or less than or equal</li>
3547 <li><tt>une</tt>: unordered or not equal</li>
3548 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3549 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3550</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3551<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3552<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3553<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3554<a href="#t_floating">floating point</a> typed. They must have identical
3555types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3556<h5>Semantics:</h5>
3557<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3558the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3559yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3560<ol>
3561 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3562 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3563 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3564 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3565 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3566 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3567 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3568 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3569 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3570 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3571 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3572 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3573 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3574 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3575 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3576 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3577 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3578 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3579 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3580 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3581 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3582 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3583 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3584 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3585 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3586 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3587 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3588 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3589</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3590
3591<h5>Example:</h5>
3592<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3593 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3594 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3595 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3596</pre>
3597</div>
3598
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3599<!-- _______________________________________________________________________ -->
3600<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3601Instruction</a> </div>
3602<div class="doc_text">
3603<h5>Syntax:</h5>
3604<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3605<h5>Overview:</h5>
3606<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3607the SSA graph representing the function.</p>
3608<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3609<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3610field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3611as arguments, with one pair for each predecessor basic block of the
3612current block. Only values of <a href="#t_firstclass">first class</a>
3613type may be used as the value arguments to the PHI node. Only labels
3614may be used as the label arguments.</p>
3615<p>There must be no non-phi instructions between the start of a basic
3616block and the PHI instructions: i.e. PHI instructions must be first in
3617a basic block.</p>
3618<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3619<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3620specified by the pair corresponding to the predecessor basic block that executed
3621just prior to the current block.</p>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3622<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3623<pre>Loop: ; Infinite loop that counts from 0 on up...<br> %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]<br> %nextindvar = add i32 %indvar, 1<br> br label %Loop<br></pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3624</div>
3625
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3626<!-- _______________________________________________________________________ -->
3627<div class="doc_subsubsection">
3628 <a name="i_select">'<tt>select</tt>' Instruction</a>
3629</div>
3630
3631<div class="doc_text">
3632
3633<h5>Syntax:</h5>
3634
3635<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3636 &lt;result&gt; = select i1 &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3637</pre>
3638
3639<h5>Overview:</h5>
3640
3641<p>
3642The '<tt>select</tt>' instruction is used to choose one value based on a
3643condition, without branching.
3644</p>
3645
3646
3647<h5>Arguments:</h5>
3648
3649<p>
3650The '<tt>select</tt>' instruction requires a boolean value indicating the condition, and two values of the same <a href="#t_firstclass">first class</a> type.
3651</p>
3652
3653<h5>Semantics:</h5>
3654
3655<p>
3656If the boolean condition evaluates to true, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3657value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3658</p>
3659
3660<h5>Example:</h5>
3661
3662<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3663 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3664</pre>
3665</div>
3666
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]3667
3668<!-- _______________________________________________________________________ -->
3669<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3670 <a name="i_call">'<tt>call</tt>' Instruction</a>
3671</div>
3672
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3673<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3674
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3675<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3676<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3677 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3678</pre>
3679
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3680<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3681
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3682<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3683
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3684<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3685
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3686<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3687
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3688<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3689 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3690 <p>The optional "tail" marker indicates whether the callee function accesses
3691 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3692 function call is eligible for tail call optimization. Note that calls may
3693 be marked "tail" even if they do not occur before a <a
3694 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3695 </li>
3696 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3697 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3698 convention</a> the call should use. If none is specified, the call defaults
3699 to using C calling conventions.
3700 </li>
3701 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3702 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3703 the type of the return value. Functions that return no value are marked
3704 <tt><a href="#t_void">void</a></tt>.</p>
3705 </li>
3706 <li>
3707 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3708 value being invoked. The argument types must match the types implied by
3709 this signature. This type can be omitted if the function is not varargs
3710 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3711 </li>
3712 <li>
3713 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3714 be invoked. In most cases, this is a direct function invocation, but
3715 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3716 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3717 </li>
3718 <li>
3719 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]3720 function signature argument types. All arguments must be of
3721 <a href="#t_firstclass">first class</a> type. If the function signature
3722 indicates the function accepts a variable number of arguments, the extra
3723 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3724 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3725</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3726
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3727<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3728
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3729<p>The '<tt>call</tt>' instruction is used to cause control flow to
3730transfer to a specified function, with its incoming arguments bound to
3731the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3732instruction in the called function, control flow continues with the
3733instruction after the function call, and the return value of the
3734function is bound to the result argument. This is a simpler case of
3735the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3736
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3737<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3738
3739<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3740 %retval = call i32 @test(i32 %argc)
3741 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3742 %X = tail call i32 @foo()
3743 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3744 %Z = call void %foo(i8 97 signext)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3745</pre>
3746
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3747</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3748
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3749<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3750<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3751 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3752</div>
3753
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3754<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3755
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3756<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3757
3758<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3759 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3760</pre>
3761
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3762<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3763
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3764<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3765the "variable argument" area of a function call. It is used to implement the
3766<tt>va_arg</tt> macro in C.</p>
3767
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3768<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3769
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3770<p>This instruction takes a <tt>va_list*</tt> value and the type of
3771the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3772increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3773actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3774
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3775<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3776
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3777<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3778type from the specified <tt>va_list</tt> and causes the
3779<tt>va_list</tt> to point to the next argument. For more information,
3780see the variable argument handling <a href="#int_varargs">Intrinsic
3781Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3782
3783<p>It is legal for this instruction to be called in a function which does not
3784take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3785function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3786
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3787<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3788href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3789argument.</p>
3790
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3791<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3792
3793<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3794
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3795</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3796
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3797<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3798<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3799<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3800
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3801<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3802
3803<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3804well known names and semantics and are required to follow certain restrictions.
3805Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3806language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]3807adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3808
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3809<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3810prefix is reserved in LLVM for intrinsic names; thus, function names may not
3811begin with this prefix. Intrinsic functions must always be external functions:
3812you cannot define the body of intrinsic functions. Intrinsic functions may
3813only be used in call or invoke instructions: it is illegal to take the address
3814of an intrinsic function. Additionally, because intrinsic functions are part
3815of the LLVM language, it is required if any are added that they be documented
3816here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3817
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3818<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3819a family of functions that perform the same operation but on different data
3820types. Because LLVM can represent over 8 million different integer types,
3821overloading is used commonly to allow an intrinsic function to operate on any
3822integer type. One or more of the argument types or the result type can be
3823overloaded to accept any integer type. Argument types may also be defined as
3824exactly matching a previous argument's type or the result type. This allows an
3825intrinsic function which accepts multiple arguments, but needs all of them to
3826be of the same type, to only be overloaded with respect to a single argument or
3827the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3828
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3829<p>Overloaded intrinsics will have the names of its overloaded argument types
3830encoded into its function name, each preceded by a period. Only those types
3831which are overloaded result in a name suffix. Arguments whose type is matched
3832against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3833take an integer of any width and returns an integer of exactly the same integer
3834width. This leads to a family of functions such as
3835<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3836Only one type, the return type, is overloaded, and only one type suffix is
3837required. Because the argument's type is matched against the return type, it
3838does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3839
3840<p>To learn how to add an intrinsic function, please see the
3841<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3842</p>
3843
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3844</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3845
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3846<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3847<div class="doc_subsection">
3848 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3849</div>
3850
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3851<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3852
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3853<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3854 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3855intrinsic functions. These functions are related to the similarly
3856named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3857
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3858<p>All of these functions operate on arguments that use a
3859target-specific value type "<tt>va_list</tt>". The LLVM assembly
3860language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3861transformations should be prepared to handle these functions regardless of
3862the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3863
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]3864<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3865instruction and the variable argument handling intrinsic functions are
3866used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3867
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3868<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3869<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3870define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3871 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3872 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3873 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3874 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3875
3876 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3877 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3878
3879 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3880 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3881 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3882 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3883 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3884
3885 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3886 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3887 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3888}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3889
3890declare void @llvm.va_start(i8*)
3891declare void @llvm.va_copy(i8*, i8*)
3892declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3893</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3894</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3895
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3896</div>
3897
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3898<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3899<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3900 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3901</div>
3902
3903
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3904<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3905<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3906<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3907<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3908<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3909<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3910href="#i_va_arg">va_arg</a></tt>.</p>
3911
3912<h5>Arguments:</h5>
3913
3914<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3915
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3916<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3917
3918<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3919macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3920<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3921<tt>va_arg</tt> will produce the first variable argument passed to the function.
3922Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3923last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3924
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3925</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3926
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3927<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3928<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3929 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3930</div>
3931
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3932<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3933<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3934<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3935<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3936
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3937<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3938which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3939or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3940
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3941<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3942
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3943<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3944
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3945<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3946
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3947<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3948macro available in C. In a target-dependent way, it destroys the
3949<tt>va_list</tt> element to which the argument points. Calls to <a
3950href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3951<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3952<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3953
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3954</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3955
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3956<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3957<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3958 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3959</div>
3960
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3961<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3962
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3963<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3964
3965<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3966 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3967</pre>
3968
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3969<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3970
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3971<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3972from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3973
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3974<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3975
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3976<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharthd0a4c622005-06-22 20:38:11 +0000[diff] [blame]3977The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3978
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3979
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3980<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3981
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3982<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3983macro available in C. In a target-dependent way, it copies the source
3984<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3985intrinsic is necessary because the <tt><a href="#int_va_start">
3986llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3987example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3988
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3989</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3990
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3991<!-- ======================================================================= -->
3992<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3993 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3994</div>
3995
3996<div class="doc_text">
3997
3998<p>
3999LLVM support for <a href="GarbageCollection.html">Accurate Garbage
4000Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4001These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4002stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4003href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4004Front-ends for type-safe garbage collected languages should generate these
4005intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4006href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4007</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]4008
4009<p>The garbage collection intrinsics only operate on objects in the generic
4010 address space (address space zero).</p>
4011
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4012</div>
4013
4014<!-- _______________________________________________________________________ -->
4015<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4016 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4017</div>
4018
4019<div class="doc_text">
4020
4021<h5>Syntax:</h5>
4022
4023<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4024 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4025</pre>
4026
4027<h5>Overview:</h5>
4028
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]4029<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4030the code generator, and allows some metadata to be associated with it.</p>
4031
4032<h5>Arguments:</h5>
4033
4034<p>The first argument specifies the address of a stack object that contains the
4035root pointer. The second pointer (which must be either a constant or a global
4036value address) contains the meta-data to be associated with the root.</p>
4037
4038<h5>Semantics:</h5>
4039
4040<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
4041location. At compile-time, the code generator generates information to allow
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4042the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4043intrinsic may only be used in a function which <a href="#gc">specifies a GC
4044algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4045
4046</div>
4047
4048
4049<!-- _______________________________________________________________________ -->
4050<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4051 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4052</div>
4053
4054<div class="doc_text">
4055
4056<h5>Syntax:</h5>
4057
4058<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4059 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4060</pre>
4061
4062<h5>Overview:</h5>
4063
4064<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4065locations, allowing garbage collector implementations that require read
4066barriers.</p>
4067
4068<h5>Arguments:</h5>
4069
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4070<p>The second argument is the address to read from, which should be an address
4071allocated from the garbage collector. The first object is a pointer to the
4072start of the referenced object, if needed by the language runtime (otherwise
4073null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4074
4075<h5>Semantics:</h5>
4076
4077<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4078instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4079garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4080may only be used in a function which <a href="#gc">specifies a GC
4081algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4082
4083</div>
4084
4085
4086<!-- _______________________________________________________________________ -->
4087<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4088 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4089</div>
4090
4091<div class="doc_text">
4092
4093<h5>Syntax:</h5>
4094
4095<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4096 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4097</pre>
4098
4099<h5>Overview:</h5>
4100
4101<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4102locations, allowing garbage collector implementations that require write
4103barriers (such as generational or reference counting collectors).</p>
4104
4105<h5>Arguments:</h5>
4106
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4107<p>The first argument is the reference to store, the second is the start of the
4108object to store it to, and the third is the address of the field of Obj to
4109store to. If the runtime does not require a pointer to the object, Obj may be
4110null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4111
4112<h5>Semantics:</h5>
4113
4114<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4115instruction, but may be replaced with substantially more complex code by the
Gordon Henriksene1433f22007-12-25 02:31:26 +0000[diff] [blame]4116garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4117may only be used in a function which <a href="#gc">specifies a GC
4118algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4119
4120</div>
4121
4122
4123
4124<!-- ======================================================================= -->
4125<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4126 <a name="int_codegen">Code Generator Intrinsics</a>
4127</div>
4128
4129<div class="doc_text">
4130<p>
4131These intrinsics are provided by LLVM to expose special features that may only
4132be implemented with code generator support.
4133</p>
4134
4135</div>
4136
4137<!-- _______________________________________________________________________ -->
4138<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4139 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4140</div>
4141
4142<div class="doc_text">
4143
4144<h5>Syntax:</h5>
4145<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4146 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4147</pre>
4148
4149<h5>Overview:</h5>
4150
4151<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4152The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4153target-specific value indicating the return address of the current function
4154or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4155</p>
4156
4157<h5>Arguments:</h5>
4158
4159<p>
4160The argument to this intrinsic indicates which function to return the address
4161for. Zero indicates the calling function, one indicates its caller, etc. The
4162argument is <b>required</b> to be a constant integer value.
4163</p>
4164
4165<h5>Semantics:</h5>
4166
4167<p>
4168The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4169the return address of the specified call frame, or zero if it cannot be
4170identified. The value returned by this intrinsic is likely to be incorrect or 0
4171for arguments other than zero, so it should only be used for debugging purposes.
4172</p>
4173
4174<p>
4175Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4176aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4177source-language caller.
4178</p>
4179</div>
4180
4181
4182<!-- _______________________________________________________________________ -->
4183<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4184 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4185</div>
4186
4187<div class="doc_text">
4188
4189<h5>Syntax:</h5>
4190<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4191 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4192</pre>
4193
4194<h5>Overview:</h5>
4195
4196<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4197The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4198target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4199</p>
4200
4201<h5>Arguments:</h5>
4202
4203<p>
4204The argument to this intrinsic indicates which function to return the frame
4205pointer for. Zero indicates the calling function, one indicates its caller,
4206etc. The argument is <b>required</b> to be a constant integer value.
4207</p>
4208
4209<h5>Semantics:</h5>
4210
4211<p>
4212The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4213the frame address of the specified call frame, or zero if it cannot be
4214identified. The value returned by this intrinsic is likely to be incorrect or 0
4215for arguments other than zero, so it should only be used for debugging purposes.
4216</p>
4217
4218<p>
4219Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4220aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4221source-language caller.
4222</p>
4223</div>
4224
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4225<!-- _______________________________________________________________________ -->
4226<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4227 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4228</div>
4229
4230<div class="doc_text">
4231
4232<h5>Syntax:</h5>
4233<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4234 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4235</pre>
4236
4237<h5>Overview:</h5>
4238
4239<p>
4240The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4241the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4242<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4243features like scoped automatic variable sized arrays in C99.
4244</p>
4245
4246<h5>Semantics:</h5>
4247
4248<p>
4249This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4250href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4251<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4252<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4253state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4254practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4255that were allocated after the <tt>llvm.stacksave</tt> was executed.
4256</p>
4257
4258</div>
4259
4260<!-- _______________________________________________________________________ -->
4261<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4262 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4263</div>
4264
4265<div class="doc_text">
4266
4267<h5>Syntax:</h5>
4268<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4269 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4270</pre>
4271
4272<h5>Overview:</h5>
4273
4274<p>
4275The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4276the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4277href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4278useful for implementing language features like scoped automatic variable sized
4279arrays in C99.
4280</p>
4281
4282<h5>Semantics:</h5>
4283
4284<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4285See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4286</p>
4287
4288</div>
4289
4290
4291<!-- _______________________________________________________________________ -->
4292<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4293 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4294</div>
4295
4296<div class="doc_text">
4297
4298<h5>Syntax:</h5>
4299<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4300 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4301</pre>
4302
4303<h5>Overview:</h5>
4304
4305
4306<p>
4307The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4308a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4309no
4310effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4311characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4312</p>
4313
4314<h5>Arguments:</h5>
4315
4316<p>
4317<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4318determining if the fetch should be for a read (0) or write (1), and
4319<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4320locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4321<tt>locality</tt> arguments must be constant integers.
4322</p>
4323
4324<h5>Semantics:</h5>
4325
4326<p>
4327This intrinsic does not modify the behavior of the program. In particular,
4328prefetches cannot trap and do not produce a value. On targets that support this
4329intrinsic, the prefetch can provide hints to the processor cache for better
4330performance.
4331</p>
4332
4333</div>
4334
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4335<!-- _______________________________________________________________________ -->
4336<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4337 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4338</div>
4339
4340<div class="doc_text">
4341
4342<h5>Syntax:</h5>
4343<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4344 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4345</pre>
4346
4347<h5>Overview:</h5>
4348
4349
4350<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4351The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4352(PC) in a region of
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4353code to simulators and other tools. The method is target specific, but it is
4354expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen25d4f7e2005-11-11 02:15:27 +0000[diff] [blame]4355The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnerd07c3f42005-11-15 06:07:55 +0000[diff] [blame]4356after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4357optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4358correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4359</p>
4360
4361<h5>Arguments:</h5>
4362
4363<p>
4364<tt>id</tt> is a numerical id identifying the marker.
4365</p>
4366
4367<h5>Semantics:</h5>
4368
4369<p>
4370This intrinsic does not modify the behavior of the program. Backends that do not
4371support this intrinisic may ignore it.
4372</p>
4373
4374</div>
4375
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4376<!-- _______________________________________________________________________ -->
4377<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4378 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4379</div>
4380
4381<div class="doc_text">
4382
4383<h5>Syntax:</h5>
4384<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4385 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4386</pre>
4387
4388<h5>Overview:</h5>
4389
4390
4391<p>
4392The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4393counter register (or similar low latency, high accuracy clocks) on those targets
4394that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4395As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4396should only be used for small timings.
4397</p>
4398
4399<h5>Semantics:</h5>
4400
4401<p>
4402When directly supported, reading the cycle counter should not modify any memory.
4403Implementations are allowed to either return a application specific value or a
4404system wide value. On backends without support, this is lowered to a constant 0.
4405</p>
4406
4407</div>
4408
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4409<!-- ======================================================================= -->
4410<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4411 <a name="int_libc">Standard C Library Intrinsics</a>
4412</div>
4413
4414<div class="doc_text">
4415<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4416LLVM provides intrinsics for a few important standard C library functions.
4417These intrinsics allow source-language front-ends to pass information about the
4418alignment of the pointer arguments to the code generator, providing opportunity
4419for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4420</p>
4421
4422</div>
4423
4424<!-- _______________________________________________________________________ -->
4425<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4426 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4427</div>
4428
4429<div class="doc_text">
4430
4431<h5>Syntax:</h5>
4432<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4433 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4434 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4435 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4436 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4437</pre>
4438
4439<h5>Overview:</h5>
4440
4441<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4442The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4443location to the destination location.
4444</p>
4445
4446<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4447Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4448intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4449</p>
4450
4451<h5>Arguments:</h5>
4452
4453<p>
4454The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4455the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4456specifying the number of bytes to copy, and the fourth argument is the alignment
4457of the source and destination locations.
4458</p>
4459
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4460<p>
4461If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4462the caller guarantees that both the source and destination pointers are aligned
4463to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4464</p>
4465
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4466<h5>Semantics:</h5>
4467
4468<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4469The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4470location to the destination location, which are not allowed to overlap. It
4471copies "len" bytes of memory over. If the argument is known to be aligned to
4472some boundary, this can be specified as the fourth argument, otherwise it should
4473be set to 0 or 1.
4474</p>
4475</div>
4476
4477
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4478<!-- _______________________________________________________________________ -->
4479<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4480 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4481</div>
4482
4483<div class="doc_text">
4484
4485<h5>Syntax:</h5>
4486<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4487 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4488 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4489 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4490 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4491</pre>
4492
4493<h5>Overview:</h5>
4494
4495<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4496The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4497location to the destination location. It is similar to the
4498'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4499</p>
4500
4501<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4502Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4503intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4504</p>
4505
4506<h5>Arguments:</h5>
4507
4508<p>
4509The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4510the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4511specifying the number of bytes to copy, and the fourth argument is the alignment
4512of the source and destination locations.
4513</p>
4514
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4515<p>
4516If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4517the caller guarantees that the source and destination pointers are aligned to
4518that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4519</p>
4520
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4521<h5>Semantics:</h5>
4522
4523<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4524The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4525location to the destination location, which may overlap. It
4526copies "len" bytes of memory over. If the argument is known to be aligned to
4527some boundary, this can be specified as the fourth argument, otherwise it should
4528be set to 0 or 1.
4529</p>
4530</div>
4531
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4532
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4533<!-- _______________________________________________________________________ -->
4534<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4535 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4536</div>
4537
4538<div class="doc_text">
4539
4540<h5>Syntax:</h5>
4541<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4542 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4543 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4544 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4545 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4546</pre>
4547
4548<h5>Overview:</h5>
4549
4550<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4551The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4552byte value.
4553</p>
4554
4555<p>
4556Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4557does not return a value, and takes an extra alignment argument.
4558</p>
4559
4560<h5>Arguments:</h5>
4561
4562<p>
4563The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4564byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4565argument specifying the number of bytes to fill, and the fourth argument is the
4566known alignment of destination location.
4567</p>
4568
4569<p>
4570If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4571the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4572</p>
4573
4574<h5>Semantics:</h5>
4575
4576<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4577The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4578the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4579destination location. If the argument is known to be aligned to some boundary,
4580this can be specified as the fourth argument, otherwise it should be set to 0 or
45811.
4582</p>
4583</div>
4584
4585
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4586<!-- _______________________________________________________________________ -->
4587<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4588 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4589</div>
4590
4591<div class="doc_text">
4592
4593<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4594<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4595floating point or vector of floating point type. Not all targets support all
4596types however.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4597<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4598 declare float @llvm.sqrt.f32(float %Val)
4599 declare double @llvm.sqrt.f64(double %Val)
4600 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4601 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4602 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4603</pre>
4604
4605<h5>Overview:</h5>
4606
4607<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4608The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4609returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4610<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4611negative numbers (which allows for better optimization).
4612</p>
4613
4614<h5>Arguments:</h5>
4615
4616<p>
4617The argument and return value are floating point numbers of the same type.
4618</p>
4619
4620<h5>Semantics:</h5>
4621
4622<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]4623This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4624floating point number.
4625</p>
4626</div>
4627
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4628<!-- _______________________________________________________________________ -->
4629<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4630 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4631</div>
4632
4633<div class="doc_text">
4634
4635<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4636<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4637floating point or vector of floating point type. Not all targets support all
4638types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4639<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4640 declare float @llvm.powi.f32(float %Val, i32 %power)
4641 declare double @llvm.powi.f64(double %Val, i32 %power)
4642 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4643 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4644 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4645</pre>
4646
4647<h5>Overview:</h5>
4648
4649<p>
4650The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4651specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4652multiplications is not defined. When a vector of floating point type is
4653used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4654</p>
4655
4656<h5>Arguments:</h5>
4657
4658<p>
4659The second argument is an integer power, and the first is a value to raise to
4660that power.
4661</p>
4662
4663<h5>Semantics:</h5>
4664
4665<p>
4666This function returns the first value raised to the second power with an
4667unspecified sequence of rounding operations.</p>
4668</div>
4669
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4670<!-- _______________________________________________________________________ -->
4671<div class="doc_subsubsection">
4672 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4673</div>
4674
4675<div class="doc_text">
4676
4677<h5>Syntax:</h5>
4678<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4679floating point or vector of floating point type. Not all targets support all
4680types however.
4681<pre>
4682 declare float @llvm.sin.f32(float %Val)
4683 declare double @llvm.sin.f64(double %Val)
4684 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4685 declare fp128 @llvm.sin.f128(fp128 %Val)
4686 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4687</pre>
4688
4689<h5>Overview:</h5>
4690
4691<p>
4692The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4693</p>
4694
4695<h5>Arguments:</h5>
4696
4697<p>
4698The argument and return value are floating point numbers of the same type.
4699</p>
4700
4701<h5>Semantics:</h5>
4702
4703<p>
4704This function returns the sine of the specified operand, returning the
4705same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4706conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4707</div>
4708
4709<!-- _______________________________________________________________________ -->
4710<div class="doc_subsubsection">
4711 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4712</div>
4713
4714<div class="doc_text">
4715
4716<h5>Syntax:</h5>
4717<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4718floating point or vector of floating point type. Not all targets support all
4719types however.
4720<pre>
4721 declare float @llvm.cos.f32(float %Val)
4722 declare double @llvm.cos.f64(double %Val)
4723 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4724 declare fp128 @llvm.cos.f128(fp128 %Val)
4725 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4726</pre>
4727
4728<h5>Overview:</h5>
4729
4730<p>
4731The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4732</p>
4733
4734<h5>Arguments:</h5>
4735
4736<p>
4737The argument and return value are floating point numbers of the same type.
4738</p>
4739
4740<h5>Semantics:</h5>
4741
4742<p>
4743This function returns the cosine of the specified operand, returning the
4744same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4745conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4746</div>
4747
4748<!-- _______________________________________________________________________ -->
4749<div class="doc_subsubsection">
4750 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4751</div>
4752
4753<div class="doc_text">
4754
4755<h5>Syntax:</h5>
4756<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4757floating point or vector of floating point type. Not all targets support all
4758types however.
4759<pre>
4760 declare float @llvm.pow.f32(float %Val, float %Power)
4761 declare double @llvm.pow.f64(double %Val, double %Power)
4762 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4763 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4764 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4765</pre>
4766
4767<h5>Overview:</h5>
4768
4769<p>
4770The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4771specified (positive or negative) power.
4772</p>
4773
4774<h5>Arguments:</h5>
4775
4776<p>
4777The second argument is a floating point power, and the first is a value to
4778raise to that power.
4779</p>
4780
4781<h5>Semantics:</h5>
4782
4783<p>
4784This function returns the first value raised to the second power,
4785returning the
4786same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4787conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4788</div>
4789
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4790
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4791<!-- ======================================================================= -->
4792<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4793 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4794</div>
4795
4796<div class="doc_text">
4797<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4798LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4799These allow efficient code generation for some algorithms.
4800</p>
4801
4802</div>
4803
4804<!-- _______________________________________________________________________ -->
4805<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4806 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4807</div>
4808
4809<div class="doc_text">
4810
4811<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4812<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4813type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4814<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4815 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4816 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4817 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4818</pre>
4819
4820<h5>Overview:</h5>
4821
4822<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]4823The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4824values with an even number of bytes (positive multiple of 16 bits). These are
4825useful for performing operations on data that is not in the target's native
4826byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4827</p>
4828
4829<h5>Semantics:</h5>
4830
4831<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4832The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4833and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4834intrinsic returns an i32 value that has the four bytes of the input i32
4835swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4836i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4837<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4838additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4839</p>
4840
4841</div>
4842
4843<!-- _______________________________________________________________________ -->
4844<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4845 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4846</div>
4847
4848<div class="doc_text">
4849
4850<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4851<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4852width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4853<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4854 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4855 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4856 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4857 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4858 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4859</pre>
4860
4861<h5>Overview:</h5>
4862
4863<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]4864The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4865value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4866</p>
4867
4868<h5>Arguments:</h5>
4869
4870<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4871The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4872integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4873</p>
4874
4875<h5>Semantics:</h5>
4876
4877<p>
4878The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4879</p>
4880</div>
4881
4882<!-- _______________________________________________________________________ -->
4883<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4884 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4885</div>
4886
4887<div class="doc_text">
4888
4889<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4890<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4891integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4892<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4893 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4894 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4895 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4896 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4897 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4898</pre>
4899
4900<h5>Overview:</h5>
4901
4902<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4903The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4904leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4905</p>
4906
4907<h5>Arguments:</h5>
4908
4909<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4910The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4911integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4912</p>
4913
4914<h5>Semantics:</h5>
4915
4916<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4917The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4918in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4919of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4920</p>
4921</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4922
4923
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4924
4925<!-- _______________________________________________________________________ -->
4926<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4927 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4928</div>
4929
4930<div class="doc_text">
4931
4932<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4933<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4934integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4935<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4936 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4937 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4938 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4939 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4940 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4941</pre>
4942
4943<h5>Overview:</h5>
4944
4945<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4946The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4947trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4948</p>
4949
4950<h5>Arguments:</h5>
4951
4952<p>
4953The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4954integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4955</p>
4956
4957<h5>Semantics:</h5>
4958
4959<p>
4960The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4961in a variable. If the src == 0 then the result is the size in bits of the type
4962of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4963</p>
4964</div>
4965
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]4966<!-- _______________________________________________________________________ -->
4967<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4968 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4969</div>
4970
4971<div class="doc_text">
4972
4973<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4974<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4975on any integer bit width.
4976<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4977 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4978 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4979</pre>
4980
4981<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4982<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4983range of bits from an integer value and returns them in the same bit width as
4984the original value.</p>
4985
4986<h5>Arguments:</h5>
4987<p>The first argument, <tt>%val</tt> and the result may be integer types of
4988any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4989arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4990
4991<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4992<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4993of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4994<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4995operates in forward mode.</p>
4996<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4997right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4998only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4999<ol>
5000 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5001 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5002 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5003 to determine the number of bits to retain.</li>
5004 <li>A mask of the retained bits is created by shifting a -1 value.</li>
5005 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
5006</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]5007<p>In reverse mode, a similar computation is made except that the bits are
5008returned in the reverse order. So, for example, if <tt>X</tt> has the value
5009<tt>i16 0x0ACF (101011001111)</tt> and we apply
5010<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5011<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]5012</div>
5013
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5014<div class="doc_subsubsection">
5015 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5016</div>
5017
5018<div class="doc_text">
5019
5020<h5>Syntax:</h5>
5021<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
5022on any integer bit width.
5023<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5024 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5025 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5026</pre>
5027
5028<h5>Overview:</h5>
5029<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5030of bits in an integer value with another integer value. It returns the integer
5031with the replaced bits.</p>
5032
5033<h5>Arguments:</h5>
5034<p>The first argument, <tt>%val</tt> and the result may be integer types of
5035any bit width but they must have the same bit width. <tt>%val</tt> is the value
5036whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5037integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5038type since they specify only a bit index.</p>
5039
5040<h5>Semantics:</h5>
5041<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5042of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5043<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5044operates in forward mode.</p>
5045<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5046truncating it down to the size of the replacement area or zero extending it
5047up to that size.</p>
5048<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5049are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5050in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5051to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5052<p>In reverse mode, a similar computation is made except that the bits are
5053reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5054<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5055<h5>Examples:</h5>
5056<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5057 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5058 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5059 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5060 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5061 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5062</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5063</div>
5064
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5065<!-- ======================================================================= -->
5066<div class="doc_subsection">
5067 <a name="int_debugger">Debugger Intrinsics</a>
5068</div>
5069
5070<div class="doc_text">
5071<p>
5072The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5073are described in the <a
5074href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5075Debugging</a> document.
5076</p>
5077</div>
5078
5079
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5080<!-- ======================================================================= -->
5081<div class="doc_subsection">
5082 <a name="int_eh">Exception Handling Intrinsics</a>
5083</div>
5084
5085<div class="doc_text">
5086<p> The LLVM exception handling intrinsics (which all start with
5087<tt>llvm.eh.</tt> prefix), are described in the <a
5088href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5089Handling</a> document. </p>
5090</div>
5091
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5092<!-- ======================================================================= -->
5093<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5094 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5095</div>
5096
5097<div class="doc_text">
5098<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5099 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5100 the <tt>nest</tt> attribute, from a function. The result is a callable
5101 function pointer lacking the nest parameter - the caller does not need
5102 to provide a value for it. Instead, the value to use is stored in
5103 advance in a "trampoline", a block of memory usually allocated
5104 on the stack, which also contains code to splice the nest value into the
5105 argument list. This is used to implement the GCC nested function address
5106 extension.
5107</p>
5108<p>
5109 For example, if the function is
5110 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5111 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5112<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5113 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5114 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5115 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5116 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5117</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5118 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5119 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5120</div>
5121
5122<!-- _______________________________________________________________________ -->
5123<div class="doc_subsubsection">
5124 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5125</div>
5126<div class="doc_text">
5127<h5>Syntax:</h5>
5128<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5129declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5130</pre>
5131<h5>Overview:</h5>
5132<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5133 This fills the memory pointed to by <tt>tramp</tt> with code
5134 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5135</p>
5136<h5>Arguments:</h5>
5137<p>
5138 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5139 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5140 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5141 intrinsic. Note that the size and the alignment are target-specific - LLVM
5142 currently provides no portable way of determining them, so a front-end that
5143 generates this intrinsic needs to have some target-specific knowledge.
5144 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5145</p>
5146<h5>Semantics:</h5>
5147<p>
5148 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5149 dependent code, turning it into a function. A pointer to this function is
5150 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5151 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5152 before being called. The new function's signature is the same as that of
5153 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5154 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5155 of pointer type. Calling the new function is equivalent to calling
5156 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5157 missing <tt>nest</tt> argument. If, after calling
5158 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5159 modified, then the effect of any later call to the returned function pointer is
5160 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5161</p>
5162</div>
5163
5164<!-- ======================================================================= -->
5165<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5166 <a name="int_general">General Intrinsics</a>
5167</div>
5168
5169<div class="doc_text">
5170<p> This class of intrinsics is designed to be generic and has
5171no specific purpose. </p>
5172</div>
5173
5174<!-- _______________________________________________________________________ -->
5175<div class="doc_subsubsection">
5176 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5177</div>
5178
5179<div class="doc_text">
5180
5181<h5>Syntax:</h5>
5182<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5183 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5184</pre>
5185
5186<h5>Overview:</h5>
5187
5188<p>
5189The '<tt>llvm.var.annotation</tt>' intrinsic
5190</p>
5191
5192<h5>Arguments:</h5>
5193
5194<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5195The first argument is a pointer to a value, the second is a pointer to a
5196global string, the third is a pointer to a global string which is the source
5197file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5198</p>
5199
5200<h5>Semantics:</h5>
5201
5202<p>
5203This intrinsic allows annotation of local variables with arbitrary strings.
5204This can be useful for special purpose optimizations that want to look for these
5205 annotations. These have no other defined use, they are ignored by code
5206 generation and optimization.
5207</div>
5208
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5209<!-- _______________________________________________________________________ -->
5210<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]5211 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5212</div>
5213
5214<div class="doc_text">
5215
5216<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5217<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5218any integer bit width.
5219</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5220<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]5221 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5222 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5223 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5224 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5225 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5226</pre>
5227
5228<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5229
5230<p>
5231The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5232</p>
5233
5234<h5>Arguments:</h5>
5235
5236<p>
5237The first argument is an integer value (result of some expression),
5238the second is a pointer to a global string, the third is a pointer to a global
5239string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5240It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5241</p>
5242
5243<h5>Semantics:</h5>
5244
5245<p>
5246This intrinsic allows annotations to be put on arbitrary expressions
5247with arbitrary strings. This can be useful for special purpose optimizations
5248that want to look for these annotations. These have no other defined use, they
5249are ignored by code generation and optimization.
5250</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5251
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5252<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5253<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5254<address>
5255 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
5256 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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5259
5260 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]5261 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5262 Last modified: $Date$
5263</address>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5264</body>
5265</html>